This command sets the direction of the individual IO pins of the individual ports. Additionally, the same command can be used to set up weak pull-ups at the pins where available. See the datasheet of the PIC MCU for a description of IO ports.
The correctness of the embedded subcommands (port + mask + value) is not checked before but during their execution. If an error is detected during the execution of the subcommands the execution is aborted. If the invalid port number is specified the ERROR_DATA is returned. If the length of the very last subcommand is not 3 bytes, the error is not returned.
Request
|
NADR |
PNUM |
PCMD |
HWPID |
0 |
1 |
2 |
… |
n × 3 |
n × 3 + 1 |
n × 3 + 2 |
|
NADR |
0x09 |
0x00 |
? |
Port0 |
Mask0 |
Value0 |
… |
Portn |
Maskn |
Valuen |
n ∈ [0,17] Number of subcommands minus 1.
Port a. Specifies port to setup a direction to. 0x00=TRISA, 0x01=TRISB, …(predefined symbols PNUM_IO_TRISx) or
b. Specifies port to setup a pull-up. 0x10=WPUA, 0x11=WPUB, … (predefined symbols PNUM_IO_WPUx)
Mask Masks pins of the port.
Value a. Actual direction bits for the masked pins. 0=output, 1=input., … or
b. Pull-up state. 0=disabled, 1=enabled.
Error codes
ERROR_DATA Invalid Port value.
Response
The general response to writing request with STATUS_NO_ERROR Error code.