TCA6416A Datasheet, PDF (7/32 Pages) Texas Instruments – LOW-VOLTAGE 16-BIT I2C AND SMBus I/O EXPANDER WITH INTERRUPT OUTPUT, RESET, AND CONFIGURATION REGISTERS

TCA6416A
www.ti.com ....................................................................................................................................................................................................... SCPS194 – MAY 2009
BYTE
I²C slave address
I/O data bus
7 (MSB)
L
P07
P17
Interface Definition
BIT
6
5
4
3
H
L
L
L
P06
P05
P04
P03
P16
P15
P14
P13
2
1
0 (LSB)
L
ADDR
R/W
P02
P01
P00
P12
P11
P10
Device Address
The address of the TCA6416A is shown in Figure 4.
Slave Address
0
1
0
0
0
0
AD
DR
R/W
Fixed
Programmable
Figure 4. TCA6416A Address
ADDR
L
H
Address Reference
I²C BUS SLAVE ADDRESS
64 (decimal), 40 (hexadecimal)
66 (decimal), 42 (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 TCA6416A. 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
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