MCP23018 datasheet(21/56 Pages) MICROCHIP

Part #	MCP23018

Description	16-Bit I/O Expander with Open-Drain Outputs

PDF	56 Pages

Scroll/Zoom	100%

Manufacturer	MICROCHIP [Microchip Technology]

Direct Link	http://www.microchip.com

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21 / 56 page

DS22103A-page 21

MCP23018/MCP23S18

1.6.4

DEFAULT COMPARE REGISTER

FOR INTERRUPT-ON-CHANGE

The default comparison value is configured in the

DEFVAL register. If enabled (via GPINTEN and INT-

CON) to compare against the DEFVAL register, an

opposite value on the associated pin will cause an

interrupt to occur.

DEFVAL – DEFAULT VALUE REGISTER

R/W-0

DEF7

DEF6

DEF5

DEF4

DEF3

DEF2

DEF1

DEF0

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

DEF7:DEF0: Sets 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.

MCP23018 Datasheet(PDF) 21 Page - Microchip Technology