Read/Write a block of data from/to a single register. More...

Read/Write a block of data from/to a single register.

The DAP_TransferBlock Command read or write a data block to the same CoreSight register. A data block are multiple 32-bit values which are read or written from/to the same CoreSight register. The CoreSight register is addressed with DPBANKSEL/APBANKSEL and address lines A2, A3 (A0 = 0 and A1 = 0). The command can execute several read/write operations to a single DP/AP register.

The data transfer is aborted on a communication error:

Protocol Error
Target FAULT response
Target WAIT responses exceed configured value

DAP_TransferBlock Command:

  BYTE | BYTE *****| SHORT**********| BYTE *************| WORD *********|
> 0x06 | DAP Index | Transfer Count | Transfer Request  | Transfer Data |
 ******|***********|****************|*******************|+++++++++++++++|

DAP Index: Zero based device index of the selected JTAG device. For SWD mode the value is ignored.

Transfer Count: Number of transfers: 1 .. 65535.

Transfer Request: Contains information about requested access from host
- Bit0: APnDP: 0 = DP (Debug Port), 1 = AP (Access Port)
- Bit1: RnW: 0 = Write Register, 1 = Read Register
- Bit2: A2 := Register Address bit 2
- Bit3: A3 := Register Address bit 3

Transfer Data: register values
- for Write Register transfer request: the register values written to the CoreSight register.
- no data is sent for Read Register operations.

DAP_TransferBlock Response:

  BYTE | SHORT *********| BYTE *************| WORD *********|
< 0x06 | Transfer Count | Transfer Response | Transfer Data |
 ******|****************|*******************|+++++++++++++++|

DAP Index: Zero based device index of the selected JTAG device. For SWD mode the value is ignored.

Transfer Count: Number of transfers (1 .. 65535) that are executed.

Transfer Response: Contains information about last response from target
- Bit 2..0: ACK (Acknowledge) value:
  - 1 = OK (for SWD protocol), OK or FAULT (for JTAG protocol),
  - 2 = WAIT
  - 4 = FAULT
  - 7 = NO_ACK (no response from target)
- Bit3: Protocol Error (SWD)

Transfer Data: register values
- no data is receive for Write Register operations.
- for Read Register transfer request: the register values read from CoreSight register.