CMSIS-DAP: DAP_UART_Transfer

| CMSIS-DAP Version 2.1.1 Interface Firmware for CoreSight Debug Access Port

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DAP_UART_Transfer
UART COM Commands

Transfer data via UART. More...

Transfer data via UART.

## DAP_UART_Transfer (0x21):

Receive and Transmit data via target UART (only for transport via DAP).

DAP_UART_Transfer Request:

| BYTE | SHORT | SHORT | BYTE |
> 0x21 | Rx Count | Tx Count| Transmit data |
|******|**********|*********|+++++++++++++++|

- Rx Count: Maximum number of bytes to be read from UART receive buffer.
- Tx Count: Number of bytes in Transmit data to be transmitted.

Note
  DAP_UART_Transfer command can be used only if transport via DAP is enabled.
  If only receive is required, Tx Count can be 0.
  If only transmit is required, Rx Count can be 0.

DAP_UART_Transfer Response:

| BYTE | BYTE | SHORT | SHORT | BYTE |
< 0x21 | Status | Tx Count | Rx Count | Receive data |
|******|********|**********|**********|+++++++++++++++|

- Status:
  - Bit 0: 1 = Receive enabled, 0 = Receive disabled
  - Bit 1: 1 = Data lost detected during receive (automatically cleared)
  - Bit 2: 1 = Framing error detected (automatically cleared)
  - Bit 3: 1 = Parity error detected (automatically cleared)
  - Bit 4: 1 = Transmit enabled, 0 = Transmit disabled
  - Bit 7..5: reserved (0)
- Tx Count: Number of bytes accepted from Transmit data and queued to UART transmit buffer.
- Rx Count: Number of bytes in Receive data read from UART receive buffer.
- Receive data: Bytes received from the target device via UART.