PCA9575 Datasheet, PDF (9/38 Pages) NXP Semiconductors – 16-bit I2C-bus and SMBus, level translating, low voltage GPIO with reset and interrupt

NXP Semiconductors
PCA9575
16-bit I²C-bus and SMBus, level translating, low voltage GPIO
7.3 Command register
Following the successful acknowledgement of the slave address + R/W bit, the bus master
will send a byte to the PCA9575, which will be stored in the Command register.
AI 0 0 0 D3 D2 D1 D0
Auto-Increment flag
register address
002aad568
Fig 8.
Reset state = 00h
Remark: The Command register does not apply to Software Reset I²C-bus address.
Command register
The lowest 4 bits are used as a pointer to determine which register will be accessed. Only
a Command register code with the 4 least significant bits equal to the 16 allowable values
as defined in Table 3 “Register summary” will be acknowledged. Reserved or undefined
command codes will not be acknowledged. At power-up, this register defaults to 00h, with
the AI bit set to logic 0, and the lowest 4 bits set to logic 0.
If the Auto-Increment flag is set (AI = 1), the 4 least significant bits of the Command
register are automatically incremented after a read or write. This allows the user to
program and/or read the 16 command registers (listed in Table 3) sequentially. It will then
roll over to register 00h after the last register is accessed and the selected registers will be
overwritten or re-read.
If the Auto-Increment flag is cleared (AI = 0), the 4 least significant bits are not
incremented after data is read or written, only one register will be repeatedly read or
written.
7.4 Register definitions
Table 3. Register summary
Register number D3 D2 D1 D0 Name
00h
0 0 0 0 IN0
01h
0 0 0 1 IN1
02h
0 0 1 0 INVRT0
03h
0 0 1 1 INVRT1
04h
0 1 0 0 BKEN0
05h
0 1 0 1 BKEN1
06h
0 1 1 0 PUPD0
07h
0 1 1 1 PUPD1
08h
1 0 0 0 CFG0
09h
1 0 0 1 CFG1
0Ah
1 0 1 0 OUT0
0Bh
1 0 1 1 OUT1
0Ch
1 1 0 0 MSK0
Type
read only
read only
read/write
read/write
read/write
read/write
read/write
read/write
read/write
read/write
read/write
read/write
read/write
Function
Input port 0 register
Input port 1 register
Polarity inversion port 0 register
Polarity inversion port 1 register
Bus-hold enable 0 register
Bus-hold enable 1 register
Pull-up/pull-down selector port 0 register
Pull-up/pull-down selector port 1 register
Configuration port 0 register
Configuration port 1 register
Output port 0 register
Output port 1 register
Interrupt mask port 0 register
PCA9575_3
Product data sheet
Rev. 03 — 9 November 2009
© NXP B.V. 2009. All rights reserved.
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