Datasheet

MCP2221
DS20005292A-page 12  2014 Microchip Technology Inc.
1.4.3 GP SETTINGS MAP
The GP Settings area resides in Flash memory and is
copied into SRAM at runtime. The user can alter both
the Flash and the SRAM GP settings. Any modification
in the SRAM copy of the GP settings will has an imme-
diate effect. The GP pins designation changes accord-
ing to the new content of the SRAM settings. The Flash
variant of the settings will affect the Power-up behavior
of the GP pins.
TABLE 1-4: GP SETTINGS MAP
Byte
Index
Register
Name
Comments
0 GPSETTING0 GP0 pin designation and GPIO default output value, when GP is set for GPIO output operation
1 GPSETTING1 GP1 pin designation and GPIO default output value, when GP is set for GPIO output operation
2 GPSETTING2 GP2 pin designation and GPIO default output value, when GP is set for GPIO output operation
3 GPSETTING3 GP3 pin designation and GPIO default output value, when GP is set for GPIO output operation
REGISTER 1-12: GPSETTING0 REGISTER
R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0
— — — GPIOOUTVAL GPIODIR GPDES2 GPDES1 GPDES0
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7-5 Reserved: Set to ‘0’
bit 4 GPIOOUTVAL: GPIO Output Value (valid only when the GP0 is set for GPIO output operation)
1 = Default output value is logic ‘1’
0 = Default output value is logic ‘0’
bit 3 GPIODIR: GPIO Direction (input or output; valid only GP0 is set for GPIO operation)
1 = GPIO Input
0 = GPIO Output
bit 2-0 GPDES<2:0>: GP0 Designation
111 = Reserved
110 = Reserved
101 = Reserved
100 = Reserved
011 = Reserved
010 = Alternate function 1 (LED UART R
X – LEDURX)
001 = Dedicated function operation (SSPND)
000 = GPIO operation (GPIO0)