Signon

Used to check that serial trace is supported by the hardware.

Table 1. Signon
Field Size Description
SERIAL_TRACE 1 byte 0x87
SIGNON 1 byte 0x0F

Response:

Table 2. Signon Response
Field Size Description
SERIAL_TRACE 1 byte 0x87
SIGNON 1 byte 0x0F
Signon string 3 bytes "OK\0"
Note: Any other response than the signon string indicates that SWO trace is not supported on that hardware.