NXP Semiconductors
PCA9555
16-bit I
2
C-bus and SMBus I/O port with interrupt
6. Functional description
Refer to
6.1 Device address
slave address
0
1
0
0
A2
A1
A0 R/W
fixed
programmable
002aac219
Fig 8.
PCA9555 device address
6.2 Registers
6.2.1 Command byte
The command byte is the first byte to follow the address byte during a write transmission.
It is used as a pointer to determine which of the following registers will be written or read.
Table 4.
Command
0
1
2
3
4
5
6
7
Command byte
Register
Input port 0
Input port 1
Output port 0
Output port 1
Polarity Inversion port 0
Polarity Inversion port 1
Configuration port 0
Configuration port 1
PCA9555_8
© NXP B.V. 2009. All rights reserved.
Product data sheet
Rev. 08 — 22 October 2009
6 of 34
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