CMSIS-DAP  Version 2.1.1
Interface Firmware for CoreSight Debug Access Port
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Read/write single and multiple registers. More...

Read/write single and multiple registers.

The DAP_Transfer Command reads or writes data to CoreSight registers. Each CoreSight register is accessed with a single 32-bit read or write. The CoreSight registers are addressed with DPBANKSEL/APBANKSEL and address lines A2, A3 (A0 = 0 and A1 = 0). This command executes several read/write operations on the selected DP/AP registers. The Transfer Data in the Response are in the order of the Transfer Request in the Command but might be shorter in case of communication failures. The data transfer is aborted on a communication error:

DAP_Transfer Command:

| BYTE | BYTE *****| BYTE **********| BYTE *************| WORD *********|
> 0x05 | DAP Index | Transfer Count | Transfer Request | Transfer Data |
Transfer Request - Bit 7 (Time Stamp) cannot be combined with Bit 4 (Value Match) or Bit 5 (Match Mask).

DAP_Transfer Response:

| BYTE | BYTE **********| BYTE *************| WORD ********| WORD *********|
< 0x05 | Transfer Count | Transfer Response | TD_TimeStamp | Transfer Data |