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JTAG_Read
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Read data from an external device to the FT2232C using the JTAG protocol.

FTC_STATUS
JTAG_Read
(FTC_HANDLE ftHandle, BOOL bInstructionTestData, DWORD dwNumBitsToRead, PReadDataByteBuffer pReadDataBuffer, LPDWORD lpdwNumBytesReturned, DWORD dwTapControllerState)




Parameters
ftHandle
Handle of the device.
bInstructionTestData
Selects the instruction register (TRUE) or the test register (FALSE) to write data to.
dwNumBitsToRead
Number of bits to be read from the external device. Valid range is 2 to 524280.
pReadDataBuffer
Pointer to buffer that returns the data read from an external device. Size of buffer should be set to 65535.
lpdwNumBytesReturned
Pointer to the actual number of bytes read from the external device.
dwTapControllerState
State that the Test Access Port (TAP) controller will be left in.




Return Value
FTC_SUCCESS if successful, otherwise the return value is one of the following FTC error codes:

   FTC_INVALID_HANDLE
   FTC_INVALID_NUMBER_BITS
   FTC_NULL_READ_DATA_BUFFER_POINTER
   FTC_INVALID_TAP_CONTROLLER_STATE
   FTC_
FAILED_TO_COMPLETE_COMMAND
   FTC_IO_ERROR



Remarks
This function will read data from an external device to the FT2232C using the JTAG protocol. The data will be clocked at a rate specified by the clock divisor set by calling either the JTAG_InitDevice or JTAG_SetClock functions.

The read data byte buffer definition and valid TAP controller states are given in the
Appendix.



Example

FTC_STATUS Status = FTC_SUCCESS;
FTC_HANDLE ftHandle;
ReadDataByteBuffer ReadDataBuffer;
DWORD dwNumBytesReturned = 0;

Status = JTAG_Read(ftHandle, true, 32, &ReadDataBuffer, &dwNumBytesReturned, RUN_TEST_IDLE_STATE);