MCP23008-E/SO View Datasheet(PDF) - Microchip Technology

Part Name

Description

Manufacturer

MCP23008-E/SO

8-Bit I/O Expander with Serial Interface

Microchip Technology 

MCP23008/MCP23S08

1.6.4

DEFAULT COMPARE (DEFVAL)

REGISTER FOR INTERRUPT-ON-

CHANGE

The default comparison value is configured in the

DEFVAL register. If enabled (via GPINTEN and

INTCON) to compare against the DEFVAL register, an

opposite value on the associated pin will cause an

interrupt to occur.

REGISTER 1-4: DEFVAL – DEFAULT VALUE REGISTER (ADDR 0x03)

R/W-0

DEF7

bit 7

R/W-0

DEF6

R/W-0

DEF5

R/W-0

DEF4

R/W-0

DEF3

R/W-0

DEF2

R/W-0

DEF1

R/W-0

DEF0

bit 0

Legend:

R = Readable bit

-n = Value at POR

W = Writable bit

‘1’ = Bit is set

U = Unimplemented bit, read as ‘0’

‘0’ = Bit is cleared

x = Bit is unknown

bit 7-0

DEF7:DEF0: These bits set the compare value for pins configured for interrupt-on-change from

defaults <7:0>. Refer to INTCON.

If the associated pin level is the opposite from the register bit, an interrupt occurs.

Refer to INTCON and GPINTEN.

© 2007 Microchip Technology Inc.

DS21919D-page 13

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