7.1.5 GPIO Controlling Procedure

This section describes the typical command sequence for using the MCP2222 GPIO functions.

Configure GPIO

Configuring an I/O pin as a normal output pin:

• Read the response from Endpoint 0x84 (IN). The response can be one of the following:

  Response Code	Status	Action
  0x60	Response to the I/O Set Configuration	Continue reading
  0x20 0x60 0x64	The I/O pin is configured Invalid parameters. Device configuration is locked.	Retry with valid parameters. Unlock the device configuration and retry.

Configuring an I/O pin as an open-drain output pin:

• Send the IO_SetConfiguration command through Endpoint 0x04 (OUT), with the following parameters:

  Parameter	Value	Description
  Command	0x60	Configure I/O pin
  I/O number	0x00 0x10 0x20 ... 0x50	IO0 IO1 IO2 ... IO5
  I/O setting	0x10	Refer to the corresponding I/O setting register for the setting value

• Read the response from Endpoint 0x84 (IN). The response can be one of the following:

  Response Code	Status	Action
  0x60	Response to the I/O Set Configuration	Continue reading
  0x20 0x60 0x64	I/O is configured. Invalid parameters. Device configuration is locked.	Retry with valid parameters. Unlock the device configuration and retry.

Configuring an I/O pin as a normal input pin:

• Send the IO_SetConfiguration command through Endpoint 0x04 (OUT), with the following parameters:

  Parameter	Value	Description
  Command	0x60	Configure I/O pin
  I/O number	0x00 0x10 0x20 ... 0x50	IO0 IO1 IO2 ... IO5
  I/O setting	0x04	Refer to the corresponding I/O setting register for the setting value

• Read the response from Endpoint 0x84 (IN). The responses can be one of the following:

  Response Code	Status	Action
  0x60	Response to the I/O Set Configuration	Continue reading
  0x20 0x60 0x64	I/O is configured. Invalid parameters. Device configuration is locked.	Retry with valid parameters. Unlock the device configuration and retry.

Configuring an I/O pin as an internally pulled-up input pin

• Send the IO_SetConfiguration command through Endpoint 0x04 (OUT), with the following parameters:

  Parameter	Value	Description
  Command	0x60	Configure I/O pin
  I/O number	0x00 0x10 0x20 ... 0x50	IO0 IO1 IO2 ... IO5
  I/O setting	0x0C	Refer to the corresponding IO setting register for the setting value

• Read the response from Endpoint 0x84 (IN). The response can be one of the following:

  Response code	Status	Action
  0x60	Response to the I/O set configuration	Continue reading
  0x20 0x60 0x64	The I/O is configured. Invalid parameters. Device configuration is locked.	Retry with valid parameters. Unlock the device configuration and retry.

Controlling a GPIO:

Setting or clearing an output pin:

• Send the GPIO_Write command through Endpoint 0x04, OUT, with the following parameters:

  Parameter	Value	Description
  Command	0x64	Configure I/O pin
  I/O number and output state	0x00 0x01 0x10 0x11 ... 0x50 0x51	IO0 Low IO0 High IO1 Low IO1 High ... IO5 Low IO5 High

• Read the response from Endpoint 0x84 (IN). The response can be one of the following:

  Response Code	Status	Action
  0x64	Response to the I/O Set Configuration	Continue reading
  0x20 0x60 0x68	The I/O is written. Invalid parameters. Pin is not configured as a GPIO output.	Retry with valid parameters. Reconfigure and retry.

Reading an input pin:

• Send the GPIO_Read command through Endpoint 0x04 (OUT), with the following parameters:

  Parameter	Value	Description
  Command	0x68	Configure I/O pin
  The I/O number	0x00 0x10 ... 0x50	IO0 IO1 ... IO5

• Read the response from Endpoint 0x84 (IN). The response can be one of the following:

  Response Code	Status	Action
  0x68	Response to the I/O set configuration	Continue reading
  0x21 0x60 0x68	The I/O is read. Invalid parameters. The pin is not configures as a GPIO pin.	Retry with valid parameters. Reconfigure and retry.
  0x00 0x01	The GPIO pin is at a logical LOW level. GPIO pin is logical high.	Logical state of the pin