MCP23018/MCP23S18
with Port A and ten (10) are associated with Port B.
One register (IOCON) is shared between the two ports.
The Port A registers are identical to the Port B regis-
ters, therefore, they will be referred to without differen-
tiating between the port designation (i.e., they will not
have the “A” or “B” designator assigned) in the register
tables.
1.6
Configuration and Control
Registers
There are twenty two (22) registers associated with the
MCP23X18 as shown in Table 1-4 and Table 1-5. The
two tables show the register mapping with the two
BANK bit values. Ten (10) registers are associated
TABLE 1-4:
CONTROL REGISTER SUMMARY (IOCON.BANK = 1)
Register
Name
Address
(hex)
POR/RST
value
bit 7
bit 6
bit 5
bit 4
bit 3
bit 2
bit 1
bit 0
IODIRA
IPOLA
00
01
02
03
04
05
06
07
08
09
0A
10
11
12
13
14
15
16
17
18
19
1A
IO7
IP7
IO6
IP6
IO5
IP5
IO4
IP4
IO3
IP3
IO2
IP2
IO1
IP1
IO0
IP0
1111 1111
0000 0000
GPINTENA
DEFVALA
INTCONA
IOCON
GPINT7 GPINT6 GPINT5 GPINT4 GPINT3 GPINT2 GPINT1 GPINT0 0000 0000
DEF7
IOC7
BANK
PU7
INT7
ICP7
GP7
OL7
DEF6
IOC6
DEF5
IOC5
DEF4
IOC4
—
DEF3
IOC3
—
DEF2
IOC2
ODR
PU2
INT2
ICP2
GP2
OL2
IO2
DEF1
IOC1
INTPOL
PU1
DEF0
IOC0
0000 0000
0000 0000
MIRROR SEQOP
INTCC 0000 0000
GPPUA
INTFA
PU6
INT6
ICP6
GP6
OL6
IO6
PU5
INT5
ICP5
GP5
OL5
IO5
PU4
INT4
ICP4
GP4
OL4
IO4
PU3
INT3
ICP3
GP3
OL3
IO3
PU0
INTO
ICP0
GP0
OL0
IO0
0000 0000
0000 0000
0000 0000
0000 0000
0000 0000
1111 1111
0000 0000
INT1
ICP1
GP1
INTCAPA
GPIOA
OLATA
OL1
IODIRB
IPOLB
IO7
IO1
IP7
IP6
IP5
IP4
IP3
IP2
IP1
IP0
GPINTENB
DEFVALB
INTCONB
IOCON
GPINT7 GPINT6 GPINT5 GPINT4 GPINT3 GPINT2 GPINT1 GPINT0 0000 0000
DEF7
IOC7
BANK
PU7
DEF6
IOC6
DEF5
IOC5
DEF4
IOC4
—
DEF3
IOC3
—
DEF2
IOC2
ODR
PU2
DEF1
IOC1
INTPOL
PU1
DEF0
IOC0
0000 0000
0000 0000
MIRROR SEQOP
INTCC 0000 0000
GPPUB
INTFB
PU6
INT6
ICP6
GP6
OL6
PU5
INT5
ICP5
GP5
OL5
PU4
INT4
ICP4
GP4
OL4
PU3
INT3
ICP3
GP3
OL3
PU0
INTO
ICP0
GP0
OL0
0000 0000
0000 0000
0000 0000
0000 0000
0000 0000
INT7
ICP7
GP7
INT2
ICP2
GP2
OL2
INT1
INTCAPB
GPIOB
ICP1
GP1
OLATB
OL7
OL1
DS22103A-page 16
© 2008 Microchip Technology Inc.
MICROCHIP [ MICROCHIP ]
