6 GPIO Interface

The MCP2222 provides six configurable I/O pins. By default, each pin is configured according to its factory-default function, but it can be reconfigured as its respective alternate function pin.

Pins configured as GPIO can be controlled or read through the vendor class interface.

• Table 6-1. Factory Default and Alternate Functions

  IO0	GPIO0, Chip-select 3 (CS3), Alert 0 (ALRT0), Clear-to-send (CTS)
  IO1	GPIO1, Chip-select 2 (CS2), I2C Activity (I2CA), Request-to-send (RTS)
  IO2	GPIO2, Chip-select 1 (CS1), Alert 1 (ALRT1), RX Activity (RXA)
  IO3	Clockout (CLKO), TX Activity (TXA), I2C Timeout (I2CTO), GPIO3
  IO4	Chip-select 0 (CS0), USB Enumerated (USBCFG), Alert 2 (ALRT2), GPIO4
  IO5	Alert 3 (ALRT3), USB Suspend (USBSPND), SPI Activity (SPIA), GPIO5

  Note: Functions in bold are factory-default functions; the rest are alternate functions.