Datasheet

 2014 Microchip Technology Inc. DS20005292A-page 51
MCP2221
9 GP1 settings
Bit 7-5 Don’t
care
Bit 4: GPIO Output value When GP1 is set as an output GPIO, this value will be present at the
GP1 pin.
Bit 3: GPIO Direction
(Input/Output). Works
only when GP1 is set for
GPIO operation
1 GPIO Input mode
0 GPIO Output mode
Bit 2-0: GP0 Designation 111-101 Don’t care
100 Alternate function 3 (Interrupt Detection)
011 Alternate function 2 (LED UART TX)
010 Alternate function 1 (ADC 1)
001 Dedicated function operation (Clock Output)
000 GPIO operation
10 GP2 settings
Bit 7-5 Don’t
care
Bit 4: GPIO Output value When GP2 is set as an output GPIO, this value will be present at the
GP2 pin.
Bit 3: GPIO Direction
(Input/Output). Works
only when GP2 is set for
GPIO operation
1 GPIO Input mode
0 GPIO Output mode
Bit 2-0: GP2 Designation 111-100 Don’t care
011 Alternate function 2 (DAC1)
010 Alternate function 1 (ADC2)
001 Dedicated function operation (USBCFG)
000 GPIO operation
11 GP3 settings
Bit 7-5 Don’t
care
Bit 4: GPIO Output value When GP3 is set as an output GPIO, this value will be present at the
GP3 pin.
Bit 3: GPIO Direction
(Input/Output). Works
only when GP3 is set for
GPIO operation
1 GPIO Input mode
0 GPIO Output mode
Bit 2-0: GP3 Designation 111-100 Don’t care
011 Alternate function 2 (DAC2)
010 Alternate function 1 (ADC3)
001 Dedicated function operation (LED I2C)
000 GPIO operation
12-63 Reserved 0x00
TABLE 3-36: COMMAND STRUCTURE (CONTINUED)
Byte
Index
Function Description Value Effect