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Anonyme, 24/11/2021 14:35

 
// DOM-IGNORE-BEGIN
/*******************************************************************************
Copyright 2015 Microchip Technology Inc. (www.microchip.com)

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.

To request to license the code under the MLA license (www.microchip.com/mla_license),
please contact mla_licensing@microchip.com
*******************************************************************************/
//DOM-IGNORE-END

/*******************************************************************************
Module for Microchip USB Library

Company:
Microchip Technology Inc.

File Name:
usb_device.h

Summary:
Defines types and APIs associated with the USB device stack.

Description:
Defines types and APIs associated with the USB device stack.
*******************************************************************************/

#ifndef _USB_DEVICE_H
#define _USB_DEVICE_H

#include <stdint.h>

#include "usb_common.h"
#include "usb_config.h"

#if defined(__XC8)
#define PACKED
#define ALIGNED
#else
#define PACKED __attribute__((packed))
#define ALIGNED __attribute__((aligned))
#endif

/** DEFINITIONS ****************************************************/

//USB_HANDLE is a pointer to an entry in the BDT. This pointer can be used
// to read the length of the last transfer, the status of the last transfer,
// and various other information. Insure to initialize USB_HANDLE objects
// to NULL so that they are in a known state during their first usage.
#define USB_HANDLE void*

#define USB_EP0_ROM 0x00 //Data comes from RAM
#define USB_EP0_RAM 0x01 //Data comes from const
#define USB_EP0_BUSY 0x80 //The PIPE is busy
#define USB_EP0_INCLUDE_ZERO 0x40 //include a trailing zero packet
#define USB_EP0_NO_DATA 0x00 //no data to send
#define USB_EP0_NO_OPTIONS 0x00 //no options set

/********************************************************************
* Standard Request Codes
* USB 2.0 Spec Ref Table 9-4
*******************************************************************/

/* USB Device States as returned by USBGetDeviceState(). Only the defenitions
for these states should be used. The actual value for each state should
not be relied upon as constant and may change based on the implementation. */
typedef enum
{
/* Detached is the state in which the device is not attached to the bus. When
in the detached state a device should not have any pull-ups attached to either
the D+ or D- line. */
DETACHED_STATE
/*DOM-IGNORE-BEGIN*/ = 0x00 /*DOM-IGNORE-END*/,
/* Attached is the state in which the device is attached ot the bus but the
hub/port that it is attached to is not yet configured. */
ATTACHED_STATE
/*DOM-IGNORE-BEGIN*/ = 0x01 /*DOM-IGNORE-END*/,
/* Powered is the state in which the device is attached to the bus and the
hub/port that it is attached to is configured. */
POWERED_STATE
/*DOM-IGNORE-BEGIN*/ = 0x02 /*DOM-IGNORE-END*/,
/* Default state is the state after the device receives a RESET command from
the host. */
DEFAULT_STATE
/*DOM-IGNORE-BEGIN*/ = 0x04 /*DOM-IGNORE-END*/,
/* Address pending state is not an official state of the USB defined states.
This state is internally used to indicate that the device has received a
SET_ADDRESS command but has not received the STATUS stage of the transfer yet.
The device is should not switch addresses until after the STATUS stage is
complete. */
ADR_PENDING_STATE
/*DOM-IGNORE-BEGIN*/ = 0x08 /*DOM-IGNORE-END*/,
/* Address is the state in which the device has its own specific address on the
bus. */
ADDRESS_STATE
/*DOM-IGNORE-BEGIN*/ = 0x10 /*DOM-IGNORE-END*/,
/* Configured is the state where the device has been fully enumerated and is
operating on the bus. The device is now allowed to execute its application
specific tasks. It is also allowed to increase its current consumption to the
value specified in the configuration descriptor of the current configuration.
*/
CONFIGURED_STATE
/*DOM-IGNORE-BEGIN*/ = 0x20 /*DOM-IGNORE-END*/
} USB_DEVICE_STATE;


/* USB device stack events description here - DWF */
typedef enum
{
// Notification that a SET_CONFIGURATION() command was received (device)
EVENT_CONFIGURED
/*DOM-IGNORE-BEGIN*/ = EVENT_DEVICE_STACK_BASE /*DOM-IGNORE-END*/,

// A SET_DESCRIPTOR request was received (device)
EVENT_SET_DESCRIPTOR,

// An endpoint 0 request was received that the stack did not know how to
// handle. This is most often a request for one of the class drivers.
// Please refer to the class driver documentation for information related
// to what to do if this request is received. (device)
EVENT_EP0_REQUEST,

// // A USB transfer has completed. The data associated with this event is of
// // the data type HOST_TRANSFER_DATA if the event is generated from the host
// // stack.
// EVENT_TRANSFER,
//
// // A USB Start of Frame token has been received. This event is not
// // used by the Host stack.
// EVENT_SOF,
//
// // Device-mode resume received. This event is not used by the Host stack.
// EVENT_RESUME,
//
// // Device-mode suspend/idle event received. This event is not used by the
// // Host stack.
// EVENT_SUSPEND,
//
// // Device-mode bus reset received. This event is not used by the Host
// // stack.
// EVENT_RESET,

// // Device Mode: A setup packet received (data: SETUP_PKT). This event is
// // not used by the Host stack.
// EVENT_SETUP,

// Device-mode USB cable has been attached. This event is not used by the
// Host stack. The client driver may provide an application event when a
// device attaches.
EVENT_ATTACH,

// A user transfer was terminated by the stack. This event will pass back
// the value of the handle that was terminated. Compare this value against
// the current valid handles to determine which transfer was terminated.
EVENT_TRANSFER_TERMINATED

} USB_DEVICE_STACK_EVENTS;

/** Function Prototypes **********************************************/


/******************************************************************************/
/** External API Functions ****************************************************/
/******************************************************************************/

/**************************************************************************
Function:
void USBDeviceInit(void)

Description:
This function initializes the device stack it in the default state. The
USB module will be completely reset including all of the internal
variables, registers, and interrupt flags.

Precondition:
This function must be called before any of the other USB Device
functions can be called, including USBDeviceTasks().

Parameters:
None

Return Values:
None

Remarks:
None

**************************************************************************/
void USBDeviceInit(void);

/**************************************************************************
Function:
void USBDeviceTasks(void)

Summary:
This function is the main state machine/transaction handler of the USB
device side stack. When the USB stack is operated in "USB_POLLING" mode
(usb_config.h user option) the USBDeviceTasks() function should be called
periodically to receive and transmit packets through the stack. This
function also takes care of control transfers associated with the USB
enumeration process, and detecting various USB events (such as suspend).
This function should be called at least once every 1.8ms during the USB
enumeration process. After the enumeration process is complete (which can
be determined when USBGetDeviceState() returns CONFIGURED_STATE), the
USBDeviceTasks() handler may be called the faster of: either once
every 9.8ms, or as often as needed to make sure that the hardware USTAT
FIFO never gets full. A good rule of thumb is to call USBDeviceTasks() at
a minimum rate of either the frequency that USBTransferOnePacket() gets
called, or, once/1.8ms, whichever is faster. See the inline code comments
near the top of usb_device.c for more details about minimum timing
requirements when calling USBDeviceTasks().

When the USB stack is operated in "USB_INTERRUPT" mode, it is not necessary
to call USBDeviceTasks() from the main loop context. In the USB_INTERRUPT
mode, the USBDeviceTasks() handler only needs to execute when a USB
interrupt occurs, and therefore only needs to be called from the interrupt
context.

Description:
This function is the main state machine/transaction handler of the USB
device side stack. When the USB stack is operated in "USB_POLLING" mode
(usb_config.h user option) the USBDeviceTasks() function should be called
periodically to receive and transmit packets through the stack. This
function also takes care of control transfers associated with the USB
enumeration process, and detecting various USB events (such as suspend).
This function should be called at least once every 1.8ms during the USB
enumeration process. After the enumeration process is complete (which can
be determined when USBGetDeviceState() returns CONFIGURED_STATE), the
USBDeviceTasks() handler may be called the faster of: either once
every 9.8ms, or as often as needed to make sure that the hardware USTAT
FIFO never gets full. A good rule of thumb is to call USBDeviceTasks() at
a minimum rate of either the frequency that USBTransferOnePacket() gets
called, or, once/1.8ms, whichever is faster. See the inline code comments
near the top of usb_device.c for more details about minimum timing
requirements when calling USBDeviceTasks().

When the USB stack is operated in "USB_INTERRUPT" mode, it is not necessary
to call USBDeviceTasks() from the main loop context. In the USB_INTERRUPT
mode, the USBDeviceTasks() handler only needs to execute when a USB
interrupt occurs, and therefore only needs to be called from the interrupt
context.

Typical usage:
<code>
void main(void)
{
USBDeviceInit();
while(1)
{
USBDeviceTasks(); //Takes care of enumeration and other USB events
if((USBGetDeviceState() \< CONFIGURED_STATE) ||
(USBIsDeviceSuspended() == true))
{
//Either the device is not configured or we are suspended,
// so we don't want to execute any USB related application code
continue; //go back to the top of the while loop
}
else
{
//Otherwise we are free to run USB and non-USB related user
//application code.
UserApplication();
}
}
}
</code>

Precondition:
Make sure the USBDeviceInit() function has been called prior to calling
USBDeviceTasks() for the first time.
Remarks:
USBDeviceTasks() does not need to be called while in the USB suspend mode,
if the user application firmware in the USBCBSuspend() callback function
enables the ACTVIF USB interrupt source and put the microcontroller into
sleep mode. If the application firmware decides not to sleep the
microcontroller core during USB suspend (ex: continues running at full
frequency, or clock switches to a lower frequency), then the USBDeviceTasks()
function must still be called periodically, at a rate frequent enough to
ensure the 10ms resume recovery interval USB specification is met. Assuming
a worst case primary oscillator and PLL start up time of <5ms, then
USBDeviceTasks() should be called once every 5ms in this scenario.

When the USB cable is detached, or the USB host is not actively powering
the VBUS line to +5V nominal, the application firmware does not always have
to call USBDeviceTasks() frequently, as no USB activity will be taking
place. However, if USBDeviceTasks() is not called regularly, some
alternative means of promptly detecting when VBUS is powered (indicating
host attachment), or not powered (host powered down or USB cable unplugged)
is still needed. For self or dual self/bus powered USB applications, see
the USBDeviceAttach() and USBDeviceDetach() API documentation for additional
considerations.
*/
void USBDeviceTasks(void);


/*******************************************************************************
Function:
void USBEnableEndpoint(uint8_t ep, uint8_t options)

Summary:
This function will enable the specified endpoint with the specified
options
Description:
This function will enable the specified endpoint with the specified
options.

Typical Usage:
<code>
void USBCBInitEP(void)
{
USBEnableEndpoint(MSD_DATA_IN_EP,USB_IN_ENABLED|USB_OUT_ENABLED|USB_HANDSHAKE_ENABLED|USB_DISALLOW_SETUP);
USBMSDInit();
}
</code>

In the above example endpoint number MSD_DATA_IN_EP is being configured
for both IN and OUT traffic with handshaking enabled. Also since
MSD_DATA_IN_EP is not endpoint 0 (MSD does not allow this), then we can
explicitly disable SETUP packets on this endpoint.
Conditions:
None
Input:
uint8_t ep - the endpoint to be configured
uint8_t options - optional settings for the endpoint. The options should
be ORed together to form a single options string. The
available optional settings for the endpoint. The
options should be ORed together to form a single options
string. The available options are the following\:
* USB_HANDSHAKE_ENABLED enables USB handshaking (ACK,
NAK)
* USB_HANDSHAKE_DISABLED disables USB handshaking (ACK,
NAK)
* USB_OUT_ENABLED enables the out direction
* USB_OUT_DISABLED disables the out direction
* USB_IN_ENABLED enables the in direction
* USB_IN_DISABLED disables the in direction
* USB_ALLOW_SETUP enables control transfers
* USB_DISALLOW_SETUP disables control transfers
* USB_STALL_ENDPOINT STALLs this endpoint
Return:
None
Remarks:
None
*****************************************************************************/
void USBEnableEndpoint(uint8_t ep, uint8_t options);


/*************************************************************************
Function:
USB_HANDLE USBTransferOnePacket(uint8_t ep, uint8_t dir, uint8_t* data, uint8_t len)

Summary:
Transfers a single packet (one transaction) of data on the USB bus.

Description:
The USBTransferOnePacket() function prepares a USB endpoint
so that it may send data to the host (an IN transaction), or
receive data from the host (an OUT transaction). The
USBTransferOnePacket() function can be used both to receive and
send data to the host. This function is the primary API function
provided by the USB stack firmware for sending or receiving application
data over the USB port.

The USBTransferOnePacket() is intended for use with all application
endpoints. It is not used for sending or receiving application data
through endpoint 0 by using control transfers. Separate API
functions, such as USBEP0Receive(), USBEP0SendRAMPtr(), and
USBEP0SendROMPtr() are provided for this purpose.

The USBTransferOnePacket() writes to the Buffer Descriptor Table (BDT)
entry associated with an endpoint buffer, and sets the UOWN bit, which
prepares the USB hardware to allow the transaction to complete. The
application firmware can use the USBHandleBusy() macro to check the
status of the transaction, to see if the data has been successfully
transmitted yet.


Typical Usage
<code>
//make sure that the we are in the configured state
if(USBGetDeviceState() == CONFIGURED_STATE)
{
//make sure that the last transaction isn't busy by checking the handle
if(!USBHandleBusy(USBInHandle))
{
//Write the new data that we wish to send to the host to the INPacket[] array
INPacket[0] = USEFUL_APPLICATION_VALUE1;
INPacket[1] = USEFUL_APPLICATION_VALUE2;
//INPacket[2] = ... (fill in the rest of the packet data)

//Send the data contained in the INPacket[] array through endpoint "EP_NUM"
USBInHandle = USBTransferOnePacket(EP_NUM,IN_TO_HOST,(uint8_t*)&INPacket[0],sizeof(INPacket));
}
}
</code>

Conditions:
Before calling USBTransferOnePacket(), the following should be true.
1. The USB stack has already been initialized (USBDeviceInit() was called).
2. A transaction is not already pending on the specified endpoint. This
is done by checking the previous request using the USBHandleBusy()
macro (see the typical usage example).
3. The host has already sent a set configuration request and the
enumeration process is complete.
This can be checked by verifying that the USBGetDeviceState()
macro returns "CONFIGURED_STATE", prior to calling
USBTransferOnePacket().

Input:
uint8_t ep - The endpoint number that the data will be transmitted or
received on
uint8_t dir - The direction of the transfer
This value is either OUT_FROM_HOST or IN_TO_HOST
uint8_t* data - For IN transactions: pointer to the RAM buffer containing
the data to be sent to the host. For OUT transactions: pointer
to the RAM buffer that the received data should get written to.
uint8_t len - Length of the data needing to be sent (for IN transactions).
For OUT transactions, the len parameter should normally be set
to the endpoint size specified in the endpoint descriptor.

Return Values:
USB_HANDLE - handle to the transfer. The handle is a pointer to
the BDT entry associated with this transaction. The
status of the transaction (ex: if it is complete or still
pending) can be checked using the USBHandleBusy() macro
and supplying the USB_HANDLE provided by
USBTransferOnePacket().

Remarks:
If calling the USBTransferOnePacket() function from within the USBCBInitEP()
callback function, the set configuration is still being processed and the
USBDeviceState may not be == CONFIGURED_STATE yet. In this special case,
the USBTransferOnePacket() may still be called, but make sure that the
endpoint has been enabled and initialized by the USBEnableEndpoint()
function first.

*************************************************************************/
USB_HANDLE USBTransferOnePacket(uint8_t ep,uint8_t dir,uint8_t* data,uint8_t len);

/********************************************************************
Function:
void USBStallEndpoint(uint8_t ep, uint8_t dir)

Summary:
Configures the specified endpoint to send STALL to the host, the next
time the host tries to access the endpoint.

PreCondition:
None

Parameters:
uint8_t ep - The endpoint number that should be configured to send STALL.
uint8_t dir - The direction of the endpoint to STALL, either
IN_TO_HOST or OUT_FROM_HOST.

Return Values:
None

Remarks:
None

*******************************************************************/
void USBStallEndpoint(uint8_t ep, uint8_t dir);
/**************************************************************************
Function:
void USBCancelIO(uint8_t endpoint)

Description:
This function cancels the transfers pending on the specified endpoint.
This function can only be used after a SETUP packet is received and
before that setup packet is handled. This is the time period in which
the EVENT_EP0_REQUEST is thrown, before the event handler function
returns to the stack.

Precondition:

Parameters:
uint8_t endpoint - the endpoint number you wish to cancel the transfers for

Return Values:
None

Remarks:
None

**************************************************************************/
void USBCancelIO(uint8_t endpoint);

/**************************************************************************
Function:
void USBDeviceDetach(void)

Summary:
This function configures the USB module to "soft detach" itself from
the USB host.

Description:
This function configures the USB module to perform a "soft detach"
operation, by disabling the D+ (or D-) ~1.5k pull up resistor, which
lets the host know the device is present and attached. This will make
the host think that the device has been unplugged. This is potentially
useful, as it allows the USB device to force the host to re-enumerate
the device (on the firmware has re-enabled the USB module/pull up, by
calling USBDeviceAttach(), to "soft re-attach" to the host).

Precondition:
Should only be called when USB_INTERRUPT is defined. See remarks
section if USB_POLLING mode option is being used (usb_config.h option).

Additionally, this function should only be called from the main() loop
context. Do not call this function from within an interrupt handler, as
this function may modify global interrupt enable bits and settings.

Parameters:
None

Return Values:
None

Remarks:
If the application firmware calls USBDeviceDetach(), it is strongly
recommended that the firmware wait at least >= 80ms before calling
USBDeviceAttach(). If the firmware performs a soft detach, and then
re-attaches too soon (ex: after a few micro seconds for instance), some
hosts may interpret this as an unexpected "glitch" rather than as a
physical removal/re-attachment of the USB device. In this case the host
may simply ignore the event without re-enumerating the device. To
ensure that the host properly detects and processes the device soft
detach/re-attach, it is recommended to make sure the device remains
detached long enough to mimic a real human controlled USB
unplug/re-attach event (ex: after calling USBDeviceDetach(), do not
call USBDeviceAttach() for at least 80+ms, preferably longer.

Neither the USBDeviceDetach() or USBDeviceAttach() functions are blocking
or take long to execute. It is the application firmwares
responsibility for adding the 80+ms delay, when using these API
functions.

Note: The Windows plug and play event handler processing is fairly
slow, especially in certain versions of Windows, and for certain USB
device classes. It has been observed that some device classes need to
provide even more USB detach dwell interval (before calling
USBDeviceAttach()), in order to work correctly after re-enumeration.
If the USB device is a CDC class device, it is recommended to wait
at least 1.5 seconds or longer, before soft re-attaching to the host,
to provide the plug and play event handler enough time to finish
processing the removal event, before the re-attach occurs.

If the application is using the USB_POLLING mode option, then the
USBDeviceDetach() and USBDeviceAttach() functions are not available.
In this mode, the USB stack relies on the "#define USE_USB_BUS_SENSE_IO"
and "#define USB_BUS_SENSE" options in the
HardwareProfile � [platform name].h file.

When using the USB_POLLING mode option, and the
"#define USE_USB_BUS_SENSE_IO" definition has been commented out, then
the USB stack assumes that it should always enable the USB module at
pretty much all times. Basically, anytime the application firmware
calls USBDeviceTasks(), the firmware will automatically enable the USB
module. This mode would typically be selected if the application was
designed to be a purely bus powered device. In this case, the
application is powered from the +5V VBUS supply from the USB port, so
it is correct and sensible in this type of application to power up and
turn on the USB module, at anytime that the microcontroller is
powered (which implies the USB cable is attached and the host is also
powered).

In a self powered application, the USB stack is designed with the
intention that the user will enable the "#define USE_USB_BUS_SENSE_IO"
option in the HardwareProfile � [platform name].h file. When this
option is defined, then the USBDeviceTasks() function will automatically
check the I/O pin port value of the designated pin (based on the
#define USB_BUS_SENSE option in the HardwareProfile � [platform name].h
file), every time the application calls USBDeviceTasks(). If the
USBDeviceTasks() function is executed and finds that the pin defined by
the #define USB_BUS_SENSE is in a logic low state, then it will
automatically disable the USB module and tri-state the D+ and D- pins.
If however the USBDeviceTasks() function is executed and finds the pin
defined by the #define USB_BUS_SENSE is in a logic high state, then it
will automatically enable the USB module, if it has not already been
enabled.

**************************************************************************/
void USBDeviceDetach(void);

/*DOM-IGNORE-BEGIN*/
#if !defined(USB_INTERRUPT)
#define USBDeviceDetach()
#endif
/*DOM-IGNORE-END*/

/**************************************************************************
Function:
void USBDeviceAttach(void)

Summary:
Checks if VBUS is present, and that the USB module is not already
initalized, and if so, enables the USB module so as to signal device
attachment to the USB host.

Description:
This function indicates to the USB host that the USB device has been
attached to the bus. This function needs to be called in order for the
device to start to enumerate on the bus.

Precondition:
Should only be called when USB_INTERRUPT is defined. Also, should only
be called from the main() loop context. Do not call USBDeviceAttach()
from within an interrupt handler, as the USBDeviceAttach() function
may modify global interrupt enable bits and settings.

For normal USB devices:
Make sure that if the module was previously on, that it has been turned off
for a long time (ex: 100ms+) before calling this function to re-enable the module.
If the device turns off the D+ (for full speed) or D- (for low speed) ~1.5k ohm
pull up resistor, and then turns it back on very quickly, common hosts will sometimes
reject this event, since no human could ever unplug and re-attach a USB device in a
microseconds (or nanoseconds) timescale. The host could simply treat this as some kind
of glitch and ignore the event altogether.
Parameters:
None

Return Values:
None

Remarks:
See also the USBDeviceDetach() API function documentation.
****************************************************************************/
void USBDeviceAttach(void);

/*DOM-IGNORE-BEGIN*/
#if !defined(USB_INTERRUPT)
#define USBDeviceAttach()
#endif
/*DOM-IGNORE-END*/


/*******************************************************************************
Function: void USBCtrlEPAllowStatusStage(void);

Summary: This function prepares the proper endpoint 0 IN or endpoint 0 OUT
(based on the controlTransferState) to allow the status stage packet
of a control transfer to complete. This function gets used
internally by the USB stack itself, but it may also be called from
the application firmware, IF the application firmware called
the USBDeferStatusStage() function during the initial processing
of the control transfer request. In this case, the application
must call the USBCtrlEPAllowStatusStage() once, after it has fully
completed processing and handling the data stage portion of the
request.

If the application firmware has no need for delaying control
transfers, and therefore never calls USBDeferStatusStage(), then the
application firmware should not call USBCtrlEPAllowStatusStage().

Description:

Conditions:
None

Input:

Return:

Remarks:
None
*****************************************************************************/
void USBCtrlEPAllowStatusStage(void);



/*******************************************************************************
Function: void USBCtrlEPAllowDataStage(void);

Summary: This function allows the data stage of either a host-to-device or
device-to-host control transfer (with data stage) to complete.
This function is meant to be used in conjunction with either the
USBDeferOUTDataStage() or USBDeferINDataStage(). If the firmware
does not call either USBDeferOUTDataStage() or USBDeferINDataStage(),
then the firmware does not need to manually call
USBCtrlEPAllowDataStage(), as the USB stack will call this function
instead.

Description:

Conditions: A control transfer (with data stage) should already be pending,
if the firmware calls this function. Additionally, the firmware
should have called either USBDeferOUTDataStage() or
USBDeferINDataStage() at the start of the control transfer, if
the firmware will be calling this function manually.

Input:

Return:

Remarks:
*****************************************************************************/
void USBCtrlEPAllowDataStage(void);


/*******************************************************************************
Function: void USBDeferOUTDataStage(void);

Summary: This function will cause the USB hardware to continuously NAK the
OUT data packets sent from the host, during the data stage of a
device to host control transfer. This allows the firmware more time
to prepare the RAM buffer that will eventually be used to receive the
data from the host. This is also useful, if the firmware wishes to
receive the OUT data in a different context than what the
USBDeviceTasks() function executes at.

Calling this function (macro) will assert ownership of the currently
pending control transfer. Therefore, the USB stack will not STALL
when it reaches the data stage of the control transfer, even if the
firmware has not (yet) called the USBEP0Receive() API function.
However, the application firmware must still (eventually, once it is
ready) call one of the aforementioned API function.

Example Usage:

1. Host sends a SETUP packet to the device, requesting a host to
device control transfer, with data stage (OUT data packets).
2. USBDeviceTasks() executes, and then calls the USBCBCheckOtherReq()
callback event handler. The USBCBCheckOtherReq() calls the
application specific/device class specific handler that detects
the type of control transfer.
3. If the firmware needs more time before it wishes to receive the
first OUT data packet, or, if the firmware wishes to process the
command in a different context, then it may call
USBDeferOUTDataStage(), in the context of the
USBCBCheckOtherReq() handler function.
4. If the firmware called USBDeferOUTDataStage() in step #3 above,
then the hardware will NAK the OUT data packets sent by the
host, for the OUT data stage.
5. Once the firmware is ready, it should then call USBEP0Receive(),
to prepare the USB stack to receive the OUT data from the host,
and to write it to the user specified buffer.
6. The firmware should now call USBCtrlEPAllowDataStage(). This
will allow the data stage to complete. Once all OUT data has
been received, the user callback function (provided by the
function pointer provided when calling USBEP0Receive()) will
get called.
7. Once all data has been received from the host, the status stage
(a 0-byte IN packet) will complete automatically (assuming the
firmware did not call USBDeferStatusStage() during step #3).


Description:

Conditions: Before calling USBDeferOUTDataStage(), the firmware should first
verify that the control transfer has a data stage, and that
it is of type host-to-device (OUT).

Input:

Return:

Remarks: Section 9.2.6 of the official USB 2.0 specifications indicates that
the USB device must be able to receive all bytes and complete the
control transfer within a maximum of 5 seconds.

If the firmware calls USBDeferOUTDataStage(), it must eventually call
USBEP0Receive(), and then call USBCtrlEPAllowDataStage(). If it does
not do this, the control transfer will never be able to complete.
This will break the USB connection, as the host needs to be able to
communicate over EP0, in order to perform basic tasks including
enumeration.

The firmware should never call both USBDeferINDataStage() and
USBDeferOUTDataStage() during the same control transfer. These
functions are mutually exclusive (a control transfer with data stage
can never contain both IN and OUT data packets during the data stage).
*****************************************************************************/
void USBDeferOUTDataStage(void);
extern volatile bool USBDeferOUTDataStagePackets;
/*DOM-IGNORE-BEGIN*/
#define USBDeferOUTDataStage() {USBDeferOUTDataStagePackets = true; outPipes[0].info.bits.busy = 1;}
/*DOM-IGNORE-END*/

/*******************************************************************************
Function: void USBDeferStatusStage(void);

Summary: Calling this function will prevent the USB stack from automatically
enabling the status stage for the currently pending control transfer
from completing immediately after all data bytes have been sent or
received. This is useful if a class handler or USB application
firmware project uses control transfers for sending/receiving data
over EP0, but requires time in order to finish processing and/or to
consume the data.

For example: Consider an application which receives OUT data from the
USB host, through EP0 using control transfers. Now assume that this
application wishes to do something time consuming with this data (ex:
transmit it to and save it to an external EEPconst device, connected
via SPI/I2C/etc.). In this case, it would typically be desirable to
defer allowing the USB status stage of the control transfer to complete,
until after the data has been fully sent to the EEPconst device and saved.

If the USB class handler firmware that processes the control transfer
SETUP packet determines that it will need extra time to complete the
control transfer, it may optionally call USBDeferStatusStage(). If it
does so, it is then the responsibility of the application firmware to
eventually call USBCtrlEPAllowStatusStage(), once the firmware has
finished processing the data associated with the control transfer.

If the firmware call USBDeferStatusStage(), but never calls
USBCtrlEPAllowStatusStage(), then one of two possibilities will occur.

1. If the "USB_ENABLE_STATUS_STAGE_TIMEOUTS" option is commented in
usb_config.h, then the status stage of the control transfer will
never be able to complete. This is an error case and should be
avoided.
2. If the "USB_ENABLE_STATUS_STAGE_TIMEOUTS" option is enabled in
usb_config.h, then the USBDeviceTasks() function will
automatically call USBCtrlEPAllowStatusStage(), after the
"USB_STATUS_STAGE_TIMEOUT" has elapsed, since the last quanta of
"progress" has occurred in the control transfer. Progress is
defined as the last successful transaction completing on EP0 IN or
EP0 OUT.
Although the timeouts feature allows the status stage to
[eventually] complete, it is still preferable to manually call
USBCtrlEPAllowStatusStage() after the application firmware has
finished processing/consuming the control transfer data, as this
will allow for much faster processing of control transfers, and
therefore much higher data rates and better user responsiveness.
Description:

Conditions:
None

Input:

Return:

Remarks: If this function is called, is should get called after the SETUP
packet has arrived (the control transfer has started), but before
the USBCtrlEPServiceComplete() function has been called by the USB
stack. Therefore, the normal place to call USBDeferStatusStage()
would be from within the USBCBCheckOtherReq() handler context. For
example, in a HID application using control transfers, the
USBDeferStatusStage() function would be called from within the
USER_GET_REPORT_HANDLER or USER_SET_REPORT_HANDLER functions.
*****************************************************************************/
void USBDeferStatusStage(void);
extern volatile bool USBDeferStatusStagePacket;
/*DOM-IGNORE-BEGIN*/
#define USBDeferStatusStage() {USBDeferStatusStagePacket = true;}
/*DOM-IGNORE-END*/


/*******************************************************************************
Function: bool USBOUTDataStageDeferred(void);

Summary: Returns true if a control transfer with OUT data stage is pending,
and the firmware has called USBDeferOUTDataStage(), but has not
yet called USBCtrlEPAllowDataStage().
Returns false if a control transfer with OUT data stage is either
not pending, or the firmware did not call USBDeferOUTDataStage()
at the start of the control transfer.

This function (macro) would typically be used in the case where the
USBDeviceTasks() function executes in the interrupt context (ex:
USB_INTERRUPT option selected in usb_config.h), but the firmware
wishes to take care of handling the data stage of the control transfer
in the main loop context.

In this scenario, typical usage would be:
1. Host starts a control transfer with OUT data stage.
2. USBDeviceTasks() (in this scenario, interrupt context) executes.
3. USBDeviceTasks() calls USBCBCheckOtherReq(), which in turn
determines that the control transfer is class specific, with
OUT data stage.
4. The user code in USBCBCheckOtherReq() (also in interrupt context,
since it is called from USBDeviceTasks(), and therefore executes
at the same priority/context) calls USBDeferOUTDataStage().

5. Meanwhile, in the main loop context, a polling handler may be
periodically checking if(USBOUTDataStageDeferred() == true).
Ordinarily, it would evaluate false, but when a control transfer
becomes pending, and after the USBDeferOUTDataStage() macro has
been called (ex: in the interrupt context), the if() statement
will evaluate true. In this case, the main loop context can then
take care of receiving the data, by calling USBEP0Receive() and
USBCtrlEPAllowDataStage().

Description:

Conditions:

Input:

Return:

Remarks:
*****************************************************************************/
bool USBOUTDataStageDeferred(void);
/*DOM-IGNORE-BEGIN*/
#define USBOUTDataStageDeferred() USBDeferOUTDataStagePackets
/*DOM-IGNORE-END*/

/*******************************************************************************
Function: void USBDeferINDataStage(void);

Summary: This function will cause the USB hardware to continuously NAK the
IN token packets sent from the host, during the data stage of a
device to host control transfer. This allows the firmware more time
to process and prepare the IN data packets that will eventually be
sent to the host. This is also useful, if the firmware needs to
process/prepare the IN data in a different context than what the
USBDeviceTasks() function executes at.

Calling this function (macro) will assert ownership of the currently
pending control transfer. Therefore, the USB stack will not STALL
when it reaches the data stage of the control transfer, even if the
firmware has not (yet) called the USBEP0SendRAMPtr() or
USBEP0SendROMPtr() API function. However, the application firmware
must still (eventually, once it is ready) call one of the
aforementioned API functions.

Example Usage:

1. Host sends a SETUP packet to the device, requesting a device to
host control transfer, with data stage.
2. USBDeviceTasks() executes, and then calls the USBCBCheckOtherReq()
callback event handler. The USBCBCheckOtherReq() calls the
application specific/device class specific handler that detects
the type of control transfer.
3. If the firmware needs more time to prepare the first IN data packet,
or, if the firmware wishes to process the command in a different
context (ex: if USBDeviceTasks() executes as an interrupt handler,
but the IN data stage data needs to be prepared in the main loop
context), then it may call USBDeferINDataStage(), in the context
of the USBCBCheckOtherReq() handler function.
4. If the firmware called USBDeferINDataStage() in step #3 above,
then the hardware will NAK the IN token packets sent by the
host, for the IN data stage.
5. Once the firmware is ready, and has successfully prepared the
data to be sent to the host in fulfillment of the control
transfer, it should then call USBEP0SendRAMPtr() or
USBEP0SendROMPtr(), to prepare the USB stack to know how many
bytes to send to the host, and from what source location.
6. The firmware should now call USBCtrlEPAllowDataStage(). This
will allow the data stage to complete. The USB stack will send
the data buffer specified by the USBEP0SendRAMPtr() or
USBEP0SendROMPtr() function, when it was called.
7. Once all data has been sent to the host, or if the host performs
early termination, the status stage (a 0-byte OUT packet) will
complete automatically (assuming the firmware did not call
USBDeferStatusStage() during step #3).


Description:

Conditions: Before calling USBDeferINDataStage(), the firmware should first
verify that the control transfer has a data stage, and that
it is of type device-to-host (IN).

Input:

Return:

Remarks: Section 9.2.6 of the official USB 2.0 specifications indicates that
the USB device must return the first IN data packet within 500ms
of the start of the control transfer. In order to meet this
specification, the firmware must call USBEP0SendRAMPtr() or
USBEP0SendROMPtr(), and then call USBCtrlEPAllowDataStage(), in
less than 500ms from the start of the control transfer.

If the firmware calls USBDeferINDataStage(), it must eventually call
USBEP0SendRAMPtr() or USBEP0SendROMPtr(), and then call
USBCtrlEPAllowDataStage(). If it does not do this, the control
transfer will never be able to complete.

The firmware should never call both USBDeferINDataStage() and
USBDeferOUTDataStage() during the same control transfer. These
functions are mutually exclusive (a control transfer with data stage
can never contain both IN and OUT data packets during the data stage).
*****************************************************************************/
void USBDeferINDataStage(void);
extern volatile bool USBDeferINDataStagePackets;
/*DOM-IGNORE-BEGIN*/
#define USBDeferINDataStage() {USBDeferINDataStagePackets = true; inPipes[0].info.bits.busy = 1;}
/*DOM-IGNORE-END*/



/*******************************************************************************
Function: bool USBINDataStageDeferred(void);

Summary: Returns true if a control transfer with IN data stage is pending,
and the firmware has called USBDeferINDataStage(), but has not
yet called USBCtrlEPAllowDataStage().
Returns false if a control transfer with IN data stage is either
not pending, or the firmware did not call USBDeferINDataStage()
at the start of the control transfer.

This function (macro) would typically be used in the case where the
USBDeviceTasks() function executes in the interrupt context (ex:
USB_INTERRUPT option selected in usb_config.h), but the firmware
wishes to take care of handling the data stage of the control transfer
in the main loop context.

In this scenario, typical usage would be:
1. Host starts a control transfer with IN data stage.
2. USBDeviceTasks() (in this scenario, interrupt context) executes.
3. USBDeviceTasks() calls USBCBCheckOtherReq(), which in turn
determines that the control transfer is class specific, with
IN data stage.
4. The user code in USBCBCheckOtherReq() (also in interrupt context,
since it is called from USBDeviceTasks(), and therefore executes
at the same priority/context) calls USBDeferINDataStage().

5. Meanwhile, in the main loop context, a polling handler may be
periodically checking if(USBINDataStageDeferred() == true).
Ordinarily, it would evaluate false, but when a control transfer
becomes pending, and after the USBDeferINDataStage() macro has
been called (ex: in the interrupt context), the if() statement
will evaluate true. In this case, the main loop context can then
take care of sending the data (when ready), by calling
USBEP0SendRAMPtr() or USBEP0SendROMPtr() and
USBCtrlEPAllowDataStage().

Description:

Conditions:

Input:

Return:

Remarks:
*****************************************************************************/
bool USBINDataStageDeferred(void);
/*DOM-IGNORE-BEGIN*/
#define USBINDataStageDeferred() USBDeferINDataStagePackets
/*DOM-IGNORE-END*/



/********************************************************************
Function:
bool USBGetRemoteWakeupStatus(void)

Summary:
This function indicates if remote wakeup has been enabled by the host.
Devices that support remote wakeup should use this function to
determine if it should send a remote wakeup.

Description:
This function indicates if remote wakeup has been enabled by the host.
Devices that support remote wakeup should use this function to
determine if it should send a remote wakeup.

If a device does not support remote wakeup (the Remote wakeup bit, bit
5, of the bmAttributes field of the Configuration descriptor is set to
1), then it should not send a remote wakeup command to the PC and this
function is not of any use to the device. If a device does support
remote wakeup then it should use this function as described below.

If this function returns false and the device is suspended, it should
not issue a remote wakeup (resume).

If this function returns true and the device is suspended, it should
issue a remote wakeup (resume).

A device can add remote wakeup support by having the _RWU symbol added
in the configuration descriptor (located in the usb_descriptors.c file
in the project). This done in the 8th byte of the configuration
descriptor. For example:

<code lang="c">
const uint8_t configDescriptor1[]={
0x09, // Size
USB_DESCRIPTOR_CONFIGURATION, // descriptor type
DESC_CONFIG_WORD(0x0022), // Total length
1, // Number of interfaces
1, // Index value of this cfg
0, // Configuration string index
_DEFAULT | _SELF | _RWU, // Attributes, see usb_device.h
50, // Max power consumption in 2X mA(100mA)

//The rest of the configuration descriptor should follow
</code>

For more information about remote wakeup, see the following section of
the USB v2.0 specification available at www.usb.org:
* Section 9.2.5.2
* Table 9-10
* Section 7.1.7.7
* Section 9.4.5

Conditions:
None

Return Values:
true - Remote Wakeup has been enabled by the host
false - Remote Wakeup is not currently enabled

Remarks:
None

*******************************************************************/
bool USBGetRemoteWakeupStatus(void);
/*DOM-IGNORE-BEGIN*/
#define USBGetRemoteWakeupStatus() RemoteWakeup
/*DOM-IGNORE-END*/

/***************************************************************************
Function:
USB_DEVICE_STATE USBGetDeviceState(void)

Summary:
This function will return the current state of the device on the USB.
This function should return CONFIGURED_STATE before an application
tries to send information on the bus.
Description:
This function returns the current state of the device on the USB. This
\function is used to determine when the device is ready to communicate
on the bus. Applications should not try to send or receive data until
this function returns CONFIGURED_STATE.

It is also important that applications yield as much time as possible
to the USBDeviceTasks() function as possible while the this function
\returns any value between ATTACHED_STATE through CONFIGURED_STATE.

For more information about the various device states, please refer to
the USB specification section 9.1 available from www.usb.org.

Typical usage:
<code>
void main(void)
{
USBDeviceInit()
while(1)
{
USBDeviceTasks();
if((USBGetDeviceState() \< CONFIGURED_STATE) ||
(USBIsDeviceSuspended() == true))
{
//Either the device is not configured or we are suspended
// so we don't want to do execute any application code
continue; //go back to the top of the while loop
}
else
{
//Otherwise we are free to run user application code.
UserApplication();
}
}
}
</code>
Conditions:
None
Return Values:
USB_DEVICE_STATE - the current state of the device on the bus

Remarks:
None
***************************************************************************/
USB_DEVICE_STATE USBGetDeviceState(void);
/*DOM-IGNORE-BEGIN*/
#define USBGetDeviceState() USBDeviceState
/*DOM-IGNORE-END*/



/***************************************************************************
Function:
bool USBGetSuspendState(void)

Summary:
This function indicates if the USB port that this device is attached to is
currently suspended. When suspended, it will not be able to transfer data
over the bus.
Description:
This function indicates if the USB port that this device is attached to is
currently suspended. When suspended, it will not be able to transfer data
over the bus.
This function can be used by the application to skip over section of
code that do not need to execute if the device is unable to send data
over the bus. This function can also be used to help determine when it is
legal to perform USB remote wakeup signaling, for devices supporting this
feature.

Typical usage:
<code>
void main(void)
{
USBDeviceInit()
while(1)
{
USBDeviceTasks();
if((USBGetDeviceState() \< CONFIGURED_STATE) ||
(USBGetSuspendState() == true))
{
//Either the device is not configured or we are suspended
// so we don't want to do execute any application code
continue; //go back to the top of the while loop
}
else
{
//Otherwise we are free to run user application code.
UserApplication();
}
}
}
</code>
Conditions:
None
Return Values:
true - the USB port this device is attached to is suspended.
false - the USB port this device is attached to is not suspended.
Remarks:
This function is the same as USBIsBusSuspended().
***************************************************************************/
bool USBGetSuspendState(void);
/*DOM-IGNORE-BEGIN*/
#define USBGetSuspendState() USBBusIsSuspended
/*DOM-IGNORE-END*/

/*******************************************************************************
Function:
bool USBIsDeviceSuspended(void)

Summary:
This function indicates if the USB module is in suspend mode.

Description:
This function indicates if the USB module is in suspend mode. This function
does NOT indicate that a suspend request has been received. It only
reflects the state of the USB module.

Typical Usage:
<code>
if(USBIsDeviceSuspended() == true)
{
return;
}
// otherwise do some application specific tasks
</code>

Conditions:
None
Input:
None
Return:
None
Remarks:
None
*****************************************************************************/
bool USBIsDeviceSuspended(void);
/*DOM-IGNORE-BEGIN*/
#define USBIsDeviceSuspended() USBSuspendControl
/*DOM-IGNORE-END*/


/*******************************************************************************
Function:
bool USBIsBusSuspended(void);

Summary:
This function indicates if the USB bus is in suspend mode.

Description:
This function indicates if the USB bus is in suspend mode. This function
is typically used for checking if the conditions are consistent with
performing a USB remote wakeup sequence.

Typical Usage:
<code>
if((USBIsBusSuspended() == true) && (USBGetRemoteWakeupStatus() == true))
{
//Check if some stimulus occured, which will be used as the wakeup source
if(sw3 == 0)
{
USBCBSendResume(); //Send the remote wakeup signalling to the host
}
}
// otherwise do some other application specific tasks
</code>

Conditions:
None
Input:
None
Return:
None
Remarks:
The USBIsBusSuspended() function relies on the USBBusIsSuspended boolean
variable, which gets updated by the USBDeviceTasks() function. Therefore,
in order to be sure the return value is not "stale", it is suggested to make
sure USBDeviceTasks() has executed recently (if using USB polling mode).
*****************************************************************************/
bool USBIsBusSuspended(void);
/*DOM-IGNORE-BEGIN*/
#define USBIsBusSuspended() USBBusIsSuspended
/*DOM-IGNORE-END*/

/*******************************************************************************
Function:
void USBSoftDetach(void);

Summary:
This function performs a detach from the USB bus via software.

Description:
This function performs a detach from the USB bus via software.

Conditions:
None
Input:
None
Return:
None
Remarks:
Caution should be used when detaching from the bus. Some PC drivers and
programs may require additional time after a detach before a device can be
reattached to the bus.
*****************************************************************************/
void USBSoftDetach(void);
/*DOM-IGNORE-BEGIN*/
#define USBSoftDetach() U1CON = 0; U1IE = 0; USBDeviceState = DETACHED_STATE;
/*DOM-IGNORE-END*/


/*************************************************************************
Function:
bool USBHandleBusy(USB_HANDLE handle)

Summary:
Checks to see if the input handle is busy

Description:
Checks to see if the input handle is busy

Typical Usage
<code>
//make sure that the last transfer isn't busy by checking the handle
if(!USBHandleBusy(USBGenericInHandle))
{
//Send the data contained in the INPacket[] array out on
// endpoint USBGEN_EP_NUM
USBGenericInHandle = USBGenWrite(USBGEN_EP_NUM,(uint8_t*)&INPacket[0],sizeof(INPacket));
}
</code>

Conditions:
None
Input:
USB_HANDLE handle - handle of the transfer that you want to check the
status of
Return Values:
true - The specified handle is busy
false - The specified handle is free and available for a transfer
Remarks:
None
*************************************************************************/
bool USBHandleBusy(USB_HANDLE handle);
/*DOM-IGNORE-BEGIN*/
#if defined(__XC8__)
#define USBHandleBusy(handle) ((handle != 0x0000) && ((*(volatile uint8_t*)handle & _USIE) != 0x00))
#else
#define USBHandleBusy(handle) (handle==0?0:((volatile BDT_ENTRY*)handle)->STAT.UOWN)
#endif
/*DOM-IGNORE-END*/

/********************************************************************
Function:
uint16_t USBHandleGetLength(USB_HANDLE handle)

Summary:
Retrieves the length of the destination buffer of the input
handle

Description:
Retrieves the length of the destination buffer of the input
handle

PreCondition:
None

Parameters:
USB_HANDLE handle - the handle to the transfer you want the
address for.

Return Values:
uint16_t - length of the current buffer that the input handle
points to. If the transfer is complete then this is the
length of the data transmitted or the length of data
actually received.

Remarks:
None

*******************************************************************/
uint16_t USBHandleGetLength(USB_HANDLE handle);
/*DOM-IGNORE-BEGIN*/
#define USBHandleGetLength(handle) (((volatile BDT_ENTRY*)handle)->CNT)
/*DOM-IGNORE-END*/

/********************************************************************
Function:
uint16_t USBHandleGetAddr(USB_HANDLE)

Summary:
Retrieves the address of the destination buffer of the input
handle

Description:
Retrieves the address of the destination buffer of the input
handle

PreCondition:
None

Parameters:
USB_HANDLE handle - the handle to the transfer you want the
address for.

Return Values:
uint16_t - address of the current buffer that the input handle
points to.

Remarks:
None

*******************************************************************/
uint16_t USBHandleGetAddr(USB_HANDLE);
/*DOM-IGNORE-BEGIN*/
#define USBHandleGetAddr(handle) ConvertToVirtualAddress((((volatile BDT_ENTRY*)handle)->ADR))
/*DOM-IGNORE-END*/


/********************************************************************
Function:
USB_HANDLE USBGetNextHandle(uint8_t ep_num, uint8_t ep_dir)
Summary:
Retrieves the handle to the next endpoint BDT entry that the
USBTransferOnePacket() will use.
Description:
Retrieves the handle to the next endpoint BDT that the
USBTransferOnePacket() will use. Useful for initialization and when
ping pong buffering will be used on application endpoints.
PreCondition:
Will return NULL if the USB device has not yet been configured/the
endpoint specified has not yet been initialized by USBEnableEndpoint().
Parameters:
uint8_t ep_num - The endpoint number to get the handle for (valid
values are 1-15, 0 is not a valid input value for this API)
uint8_t ep_dir - The endpoint direction associated with the endpoint number
to get the handle for (valid values are OUT_FROM_HOST and IN_TO_HOST).
Return Values:
USB_HANDLE - Returns the USB_HANDLE (a pointer) to the BDT that will be
used next time the USBTransferOnePacket() function is called, for the
given ep_num and ep_dir
Remarks:
This API is useful for initializing USB_HANDLEs during initialization of
the application firmware. It is also useful when ping-pong buffering is
enabled, and the application firmware wishes to arm both the even and odd
BDTs for an endpoint simultaneously. In this case, the application
firmware for sending data to the host would typically be something like
follows:

<code lang="c">
USB_HANDLE Handle1;
USB_HANDLE Handle2;
USB_HANDLE* pHandle = &Handle1;
uint8_t UserDataBuffer1[64];
uint8_t UserDataBuffer2[64];
uint8_t* pDataBuffer = &UserDataBuffer1[0];

//Add some code that loads UserDataBuffer1[] with useful data to send,
//using the pDataBuffer pointer, for example:
//for(i = 0; i < 64; i++)
//{
// *pDataBuffer++ = [useful data value];
//}

//Check if the next USB endpoint BDT is available
if(!USBHandleBusy(USBGetNextHandle(ep_num, IN_TO_HOST))
{
//The endpoint is available. Send the data.
*pHandle = USBTransferOnePacket(ep_num, ep_dir, pDataBuffer, bytecount);
//Toggle the handle and buffer pointer for the next transaction
if(pHandle == &Handle1)
{
pHandle = &Handle2;
pDataBuffer = &UserDataBuffer2[0];
}
else
{
pHandle = &Handle1;
pDataBuffer = &UserDataBuffer1[0];
}
}

//The firmware can then load the next data buffer (in this case
//UserDataBuffer2)with useful data, and send it using the same
//process. For example:

//Add some code that loads UserDataBuffer2[] with useful data to send,
//using the pDataBuffer pointer, for example:
//for(i = 0; i < 64; i++)
//{
// *pDataBuffer++ = [useful data value];
//}

//Check if the next USB endpoint BDT is available
if(!USBHandleBusy(USBGetNextHandle(ep_num, IN_TO_HOST))
{
//The endpoint is available. Send the data.
*pHandle = USBTransferOnePacket(ep_num, ep_dir, pDataBuffer, bytecount);
//Toggle the handle and buffer pointer for the next transaction
if(pHandle == &Handle1)
{
pHandle = &Handle2;
pDataBuffer = &UserDataBuffer2[0];
}
else
{
pHandle = &Handle1;
pDataBuffer = &UserDataBuffer1[0];
}
}
</code>

*******************************************************************/
USB_HANDLE USBGetNextHandle(uint8_t ep_num, uint8_t ep_dir);
/*DOM-IGNORE-BEGIN*/
#define USBGetNextHandle(ep_num, ep_dir) ((ep_dir == OUT_FROM_HOST)?((USB_HANDLE)pBDTEntryOut[ep_num]):((USB_HANDLE)pBDTEntryIn[ep_num]))
/*DOM-IGNORE-END*/

/********************************************************************
Function:
void USBEP0Transmit(uint8_t options)

Summary:
Sets the address of the data to send over the
control endpoint

PreCondition:
None

Parameters:
options - the various options that you want
when sending the control data. Options are:
USB_EP0_ROM
USB_EP0_RAM
USB_EP0_BUSY
USB_EP0_INCLUDE_ZERO
USB_EP0_NO_DATA
USB_EP0_NO_OPTIONS

Return Values:
None

Remarks:
None

*******************************************************************/
void USBEP0Transmit(uint8_t options);
/*DOM-IGNORE-BEGIN*/
#define USBEP0Transmit(options) inPipes[0].info.Val = options | USB_EP0_BUSY
/*DOM-IGNORE-END*/

/*************************************************************************
Function:
void USBEP0SendRAMPtr(uint8_t* src, uint16_t size, uint8_t Options)

Summary:
Sets the source, size, and options of the data you wish to send from a
RAM source
Conditions:
None
Input:
src - address of the data to send
size - the size of the data needing to be transmitted
options - the various options that you want when sending the control
data. Options are\:
* USB_EP0_ROM
* USB_EP0_RAM
* USB_EP0_BUSY
* USB_EP0_INCLUDE_ZERO
* USB_EP0_NO_DATA
* USB_EP0_NO_OPTIONS
Remarks:
None
*************************************************************************/
void USBEP0SendRAMPtr(uint8_t* src, uint16_t size, uint8_t Options);
/*DOM-IGNORE-BEGIN*/
#define USBEP0SendRAMPtr(src,size,options) {\
inPipes[0].pSrc.bRam = src;\
inPipes[0].wCount.Val = size;\
inPipes[0].info.Val = options | USB_EP0_BUSY | USB_EP0_RAM;\
}
/*DOM-IGNORE-END*/

/**************************************************************************
Function:
void USBEP0SendROMPtr(uint8_t* src, uint16_t size, uint8_t Options)

Summary:
Sets the source, size, and options of the data you wish to send from a
const source
Conditions:
None
Input:
src - address of the data to send
size - the size of the data needing to be transmitted
options - the various options that you want when sending the control
data. Options are\:
* USB_EP0_ROM
* USB_EP0_RAM
* USB_EP0_BUSY
* USB_EP0_INCLUDE_ZERO
* USB_EP0_NO_DATA
* USB_EP0_NO_OPTIONS
Remarks:
None
**************************************************************************/
void USBEP0SendROMPtr(uint8_t* src, uint16_t size, uint8_t Options);
/*DOM-IGNORE-BEGIN*/
#define USBEP0SendROMPtr(src,size,options) {\
inPipes[0].pSrc.bRom = src;\
inPipes[0].wCount.Val = size;\
inPipes[0].info.Val = options | USB_EP0_BUSY | USB_EP0_ROM;\
}
/*DOM-IGNORE-END*/

/***************************************************************************
Function:
void USBEP0Receive(uint8_t* dest, uint16_t size, void (*function))
Summary:
Sets the destination, size, and a function to call on the completion of
the next control write.
Conditions:
None
Input:
dest - address of where the incoming data will go (make sure that this
address is directly accessible by the USB module for parts with
dedicated USB RAM this address must be in that space)
size - the size of the data being received (is almost always going to be
presented by the preceeding setup packet SetupPkt.wLength)
(*function) - a function that you want called once the data is received. If
this is specified as NULL then no function is called.
Remarks:
None
***************************************************************************/
void USBEP0Receive(uint8_t* dest, uint16_t size, void (*function));
/*DOM-IGNORE-BEGIN*/
#define USBEP0Receive(dest,size,function) {outPipes[0].pDst.bRam = dest;outPipes[0].wCount.Val = size;outPipes[0].pFunc = function;outPipes[0].info.bits.busy = 1; }
/*DOM-IGNORE-END*/

/********************************************************************
Function:
USB_HANDLE USBTxOnePacket(uint8_t ep, uint8_t* data, uint16_t len)

Summary:
Sends the specified data out the specified endpoint

PreCondition:
None

Parameters:
ep - the endpoint number you want to send the data out of
data - pointer to a user buffer that contains the data that you wish to
send to the host. Note: This RAM buffer must be accessible by
the USB module.
len - the number of bytes of data that you wish to send to the host,
in the next transaction on this endpoint. Note: this value
should always be less than or equal to the endpoint size, as
specified in the USB endpoint descriptor.

Return Values:
USB_HANDLE - Returns a pointer to the BDT entry associated with the
transaction. The firmware can check for completion
of the transaction by using the USBHandleBusy() function,
using the returned USB_HANDLE value.

Remarks:
None

*******************************************************************/
USB_HANDLE USBTxOnePacket(uint8_t ep, uint8_t* data, uint16_t len);
/*DOM-IGNORE-BEGIN*/
#define USBTxOnePacket(ep,data,len) USBTransferOnePacket(ep,IN_TO_HOST,data,len)
/*DOM-IGNORE-END*/

/********************************************************************
Function:
USB_HANDLE USBRxOnePacket(uint8_t ep, uint8_t* data, uint16_t len)

Summary:
Receives the specified data out the specified endpoint

PreCondition:
None

Parameters:
ep - The endpoint number you want to receive the data on.
data - Pointer to a user buffer where the data will go when
it arrives from the host. Note: This RAM must be USB module
accessible.
len - The len parameter should always be set to the maximum endpoint packet
size, specified in the USB descriptor for this endpoint. The host
may send <= the number of bytes as the endpoint size in the endpoint
descriptor. After the transaction is complete, the application
firmware can call USBHandleGetLength() to determine how many bytes
the host actually sent in the last transaction on this endpoint.

Return Values:
USB_HANDLE - Returns a pointer to the BDT entry associated with the
transaction. The firmware can check for completion
of the transaction by using the USBHandleBusy() function,
using the returned USB_HANDLE value.

Remarks:
None

*******************************************************************/
USB_HANDLE USBRxOnePacket(uint8_t ep, uint8_t* data, uint16_t len);
/*DOM-IGNORE-BEGIN*/
#define USBRxOnePacket(ep,data,len) USBTransferOnePacket(ep,OUT_FROM_HOST,data,len)
/*DOM-IGNORE-END*/

/*******************************************************************************
Function:
bool USB_APPLICATION_EVENT_HANDLER(uint8_t address, USB_EVENT event, void *pdata, uint16_t size);

Summary:
This function is called whenever the USB stack wants to notify the user of
an event.

Description:
This function is called whenever the USB stack wants to notify the user of
an event. This function should be implemented by the user.

Example Usage:
Conditions:
None

Input:
uint8_t address - the address of the device when the event happened
uint8_t event - The event input specifies which event happened. The
possible options are listed in the USB_DEVICE_STACK_EVENTS
enumeration.

Return:
None
Remarks:
None
*****************************************************************************/
bool USB_APPLICATION_EVENT_HANDLER(uint8_t address, USB_EVENT event, void *pdata, uint16_t size);




/**************************************************************************
Function:
void USBIncrement1msInternalTimers(void)

Description:
This function increments internal 1ms time base counters, which are
useful for application code (that can use a 1ms time base/counter), and
for certain USB event timing specific purposes.

In USB full speed applications, the application code does not need to (and should
not) explicitly call this function, as the USBDeviceTasks() function will
automatically call this function whenever a 1ms time interval has elapsed
(assuming the code is calling USBDeviceTasks() frequently enough in USB_POLLING
mode, or that USB interrupts aren't being masked for more than 1ms at a time
in USB_INTERRUPT mode).

In USB low speed applications, the application firmware is responsible for
periodically calling this function at a ~1ms rate. This can be done using
a general purpose microcontroller timer set to interrupt every 1ms for example.
If the low speed application code does not call this function, the internal timers
will not increment, and the USBGet1msTickCount() API function will not be available.
Additionally, certain USB stack operations (like control transfer timeouts)
may be unavailable.

Precondition:
This function should be called only after USBDeviceInit() has been
called (at least once at the start of the application). Ordinarily,
application code should never call this function, unless it is a low speed
USB device.

Parameters:
None

Return Values:
None

Remarks:
This function does not need to be called during USB suspend conditions, when
the USB module/stack is disabled, or when the USB cable is detached from the host.
***************************************************************************/
void USBIncrement1msInternalTimers(void);


/**************************************************************************
Function:
uint32_t USBGet1msTickCount(void)

Description:
This function retrieves a 32-bit unsigned integer that normally increments by
one every one millisecond. The count value starts from zero when the
USBDeviceInit() function is first called. See the remarks section for
details on special circumstances where the tick count will not increment.

Precondition:
This function should be called only after USBDeviceInit() has been
called (at least once at the start of the application).

Parameters:
None

Return Values:
uint32_t representing the approximate millisecond count, since the time the
USBDeviceInit() function was first called.

Remarks:
On 8-bit USB full speed devices, the internal counter is incremented on
every SOF packet detected. Therefore, it will not increment during suspend
or when the USB cable is detached. However, on 16-bit devices, the T1MSECIF
hardware interrupt source is used to increment the internal counter. Therefore,
on 16-bit devices, the count continue to increment during USB suspend or
detach events, so long as the application code has not put the microcontroller
to sleep during these events, and the application firmware is regularly
calling the USBDeviceTasks() function (or allowing it to execute, if using
USB_INTERRUPT mode operation).

In USB low speed applications, the host does not broadcast SOF packets to
the device, so the application firmware becomes responsible for calling
USBIncrement1msInternalTimers() periodically (ex: from a general purpose
timer interrupt handler), or else the returned value from this function will
not increment.

Prior to calling USBDeviceInit() for the first time the returned value will
be unpredictable.

This function is USB_INTERRUPT mode safe and may be called from main loop
code without risk of retrieving a partially updated 32-bit number.

However, this value only increments when the USBDeviceTasks() function is allowed
to execute. If USB_INTERRUPT mode is used, it is allowable to block on this
function. If however USB_POLLING mode is used, one must not block on this
function without also calling USBDeviceTasks() continuously for the blocking
duration (since the USB stack must still be allowed to execute, and the USB
stack is also responsible for updating the tick counter internally).

If the application is operating in USB_POLLING mode, this function should
only be called from the main loop context, and not from an interrupt handler,
as the returned value could be incorrect, if the main loop context code was in
the process of updating the internal count at the moment of the interrupt event.
***************************************************************************/
uint32_t USBGet1msTickCount(void);




/**************************************************************************
Function:
uint8_t USBGetTicksSinceSuspendEnd(void);

Description:
This function retrieves a 8-bit unsigned byte that represents the number
of milliseconds that have elapsed since the end of a USB suspend event.
The value saturates at 255.

Precondition:
This function should be called only after USBDeviceInit() has been
called (at least once at the start of the application).

Parameters:
None

Return Values:
uint32_t representing the current millisecond count, since the time the
USBDeviceInit() function was first called, while the USB bus was non-suspended
and the device was attached to an active host.

Remarks:
This function does not increment during USB suspend conditions, or when the USB
cable is detached from the host. Prior to calling USBDeviceInit() for the
first time the returned value will be unpredictable.

This function is USB_INTERRUPT mode safe and may be called from main loop
code without risk of retrieving a partially updated 32-bit number.

However, this value only increments when the USBDeviceTasks() function is allowed
to execute. If USB_INTERRUPT mode is used, it is allowable to block on this
function. If however USB_POLLING mode is used, one must not block on this
function without also calling USBDeviceTasks() continuously for the blocking
duration (since the USB stack must still be allowed to execute, and the USB
stack is also responsible for updating the tick counter internally).
***************************************************************************/
uint8_t USBGetTicksSinceSuspendEnd(void);
/*DOM-IGNORE-BEGIN*/
#define USBGetTicksSinceSuspendEnd() USBTicksSinceSuspendEnd
/*DOM-IGNORE-END*/



/** Section: MACROS ******************************************************/

/* The DESC_CONFIG_WORD() macro is implemented for convenience. Since the
configuration descriptor array is a uint8_t array, each entry needs to be a
uint8_t in LSB format. The DESC_CONFIG_WORD() macro breaks up a uint16_t into
the appropriate uint8_t entries in LSB.
Typical Usage:
<code>
const uint8_t configDescriptor1[]={
0x09, // Size of this descriptor in bytes
USB_DESCRIPTOR_CONFIGURATION, // CONFIGURATION descriptor type
DESC_CONFIG_WORD(0x0022), // Total length of data for this cfg
</code>
*/
#define DESC_CONFIG_WORD(a) (a&0xFF),((a>>8)&0xFF)

/* The DESC_CONFIG_uint32_t() macro is implemented for convenience. Since the
configuration descriptor array is a uint8_t array, each entry needs to be a
uint8_t in LSB format. The DESC_CONFIG_uint32_t() macro breaks up a uint32_t into
the appropriate uint8_t entries in LSB.
*/
#define DESC_CONFIG_uint32_t(a) (a&0xFF),((a>>8)&0xFF),((a>>16)&0xFF),((a>>24)&0xFF)

/* The DESC_CONFIG_uint8_t() macro is implemented for convenience. The
DESC_CONFIG_uint8_t() macro provides a consistent macro for use with a byte
when generating a configuration descriptor when using either the
DESC_CONFIG_WORD() or DESC_CONFIG_uint32_t() macros.
*/
#define DESC_CONFIG_uint8_t(a) (a)
















/* DOM-IGNORE-BEGIN */
/*******************************************************************************
********************************************************************************
********************************************************************************
This section contains implementation specific information that may vary
between releases as the implementation needs to change. This section is
included for compilation reasons only.
********************************************************************************
********************************************************************************
*******************************************************************************/

#if defined(USB_POLLING)
#define USB_VOLATILE
#else
#define USB_VOLATILE volatile
#endif

#define CTRL_TRF_RETURN void
#define CTRL_TRF_PARAMS void

typedef union
{
uint16_t Val;
uint8_t v[2];
struct
{
uint8_t LB;
uint8_t HB;
} byte;
} uint16_t_VAL;

// Definition of the PIPE structure
// This structure is used to keep track of data that is sent out
// of the stack automatically.
typedef struct PACKED
{
union PACKED
{
//Various options of pointers that are available to
// get the data from
uint8_t *bRam;
const uint8_t *bRom;
uint16_t *wRam;
const uint16_t *wRom;
}pSrc;
union PACKED
{
struct PACKED
{
//is this transfer from RAM or const?
uint8_t ctrl_trf_mem :1;
uint8_t reserved :5;
//include a zero length packet after
//data is done if data_size%ep_size = 0?
uint8_t includeZero :1;
//is this PIPE currently in use
uint8_t busy :1;
}bits;
uint8_t Val;
}info;
uint16_t_VAL ALIGNED wCount;
}IN_PIPE;

extern USB_VOLATILE IN_PIPE inPipes[];

typedef struct PACKED
{
union PACKED
{
//Various options of pointers that are available to
// get the data from
uint8_t *bRam;
uint16_t *wRam;
}pDst;
union PACKED
{
struct PACKED
{
uint8_t reserved :7;
//is this PIPE currently in use
uint8_t busy :1;
}bits;
uint8_t Val;
}info;
uint16_t_VAL wCount;
CTRL_TRF_RETURN (*pFunc)(CTRL_TRF_PARAMS);
}OUT_PIPE;

extern USB_VOLATILE bool RemoteWakeup;
extern USB_VOLATILE bool USBBusIsSuspended;
extern USB_VOLATILE USB_DEVICE_STATE USBDeviceState;
extern USB_VOLATILE uint8_t USBActiveConfiguration;
extern USB_VOLATILE uint8_t USBTicksSinceSuspendEnd;
/******************************************************************************/
/* DOM-IGNORE-END */

#include "usb_hal.h"

#endif //USB_DEVICE_H
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