TCA6416 Datasheet, PDF (8/31 Pages) Texas Instruments – LOW-VOLTAGE 16-BIT I2C AND SMBus I/O EXPANDER WITH INTERRUPT OUTPUT, RESET, AND CONFIGURATION REGISTERS

TCA6416
LOW-VOLTAGE 16-BIT I²C AND SMBus I/O EXPANDER
WITH INTERRUPT OUTPUT, RESET, AND CONFIGURATION REGISTERS
SCPS153 – DECEMBER 2007
Interface Definition
BYTE
BIT
7 (MSB)
6
5
4
3
2
I²C slave address
L
H
L
L
L
L
I/O data bus
P07
P06
P05
P04
P03
P02
P17
P16
P15
P14
P13
P12
Device Address
The address of the TCA6416 is shown in Figure 4.
Slave Address
0
1
0
0
0
0
AD
DR
R/W
Fixed
Programmable
Figure 4. TCA6416 Address
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1
ADDR
P01
P11
0 (LSB)
R/W
P00
P10
ADDR
L
H
Address Reference
I²C BUS SLAVE ADDRESS
32 (decimal), 20 (hexadecimal)
33 (decimal), 21 (hexadecimal)
The last bit of the slave address defines the operation (read or write) to be performed. A high (1) selects a read
operation, while a low (0) selects a write operation.
Control Register and Command Byte
Following the successful acknowledgment of the address byte, the bus master sends a command byte, which is
stored in the control register in the TCA6416. Three bits of this data byte state the operation (read or write) and
the internal registers (input, output, polarity inversion, or configuration) that will be affected. This register can be
written or read through the I²C bus. The command byte is sent only during a write transmission.
Once a new command has been sent, the register that was addressed continues to be accessed by reads until a
new command byte has been sent.
B7 B6 B5 B4 B3 B2 B1 B0
Figure 5. Control Register Bits
CONTROL REGISTER BITS
B7 B6 B5 B4 B3 B2 B1
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
1
0
0
0
0
0
0
1
0
0
0
0
0
1
0
0
0
0
0
0
1
0
0
0
0
0
0
1
1
0
0
0
0
0
1
1
(1) Undefined
Command Byte
COMMAND BYTE
B0
(HEX)
REGISTER
PROTOCOL
0
00
Input Port 0
Read byte
1
01
Input Port 1
Read byte
0
02
Output Port 0
Read/write byte
1
03
Output Port 1
Read/write byte
0
04
Polarity Inversion Port 0 Read/write byte
1
05
Polarity Inversion Port 1 Read/write byte
0
06
Configuration Port 0 Read/write byte
1
07
Configuration Port 1 Read/write byte
POWER-UP
DEFAULT
xxxx xxxx⁽¹⁾
xxxx xxxx
1111 1111
1111 1111
0000 0000
0000 0000
1111 1111
1111 1111
8
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