MCP23009 Microchip Technology Inc., MCP23009 Datasheet - Page 25

• Manufacturer Part Number: MCP23009
• Description: 8-bit I/o Expander With Open-drain Outputs
• Manufacturer: Microchip Technology Inc.

1.6.10
The GPIO register reflects the value on the port.
Reading from this register reads the port. Writing to this
register modifies the Output Latch (OLAT) register.
REGISTER 1-11:
© 2008 Microchip Technology Inc.
bit 7
Legend:
R = Readable bit
-n = Value at POR
bit 7-0
R/W-0
GP7
PORT REGISTER
GP7:GP0: Reflects the logic level on the pins <7:0>.
1 = Logic-high.
0 = Logic-low.
R/W-0
GP6
GPIO – GENERAL PURPOSE I/O PORT REGISTER
W = Writable bit
‘1’ = Bit is set
R/W-0
GP5
R/W-0
GP4
‘0’ = Bit is cleared
U = Unimplemented bit, read as ‘0’
MCP23009/MCP23S09
R/W-0
GP3
R/W-0
GP2
x = Bit is unknown
R/W-0
GP1
DS22121A-page 25
R/W-0
GP0
bit 0