Datasheet

© 2008 Microchip Technology Inc. DS22103A-page 19
MCP23018/MCP23S18
1.6.2 INPUT POLARITY REGISTER
This register allows the user to configure the polarity on
the corresponding GPIO port bits.
If a bit is set, the corresponding GPIO register bit will
reflect the inverted value on the pin.
REGISTER 1-4: IPOL – INPUT POLARITY PORT 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
IP7 IP6 IP5 IP4 IP3 IP2 IP1 IP0
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 7-0 IP7:IP0: Controls the polarity inversion of the input pins <7:0>
1 = GPIO register bit will reflect the opposite logic state of the input pin.
0 = GPIO register bit will reflect the same logic state of the input pin.