Advantech ITA-5831 Series, User Manual

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65 ITA-5831 User Manual
Chapter 6
G
PIO Programming
Guide
For ITA-5831, the I/O address of the above SMB_BASE is 0xF040. The correspond-
ing SMBUS slave address of PCA9554 for GPIO 00 ~ GPIO 07 on ITA-5831 is 0x40
(8 bit address).
GPIO 00 ~ GPIO 07: PCA9554 0x40 (IO0 ~ IO7)
6.2.1 Command Byte
The command byte is the first byte to follow the address byte during a write transmis-
sion. It is used as a pointer to determine which of the following registers will be writ-
ten or read. PCA9554 has a total of four registers to control GPIO.
Table 6.2: Pin Definitions
Symbol
PinDIP16, SO16,
SSOP16, TSSOP16
HVQFN16 SSOP20 Description
A0 1 15 6 Address input 0
A1 2 16 7 Address input 1
A2 3 1 9 Address input 2
IO0 4 2 10 Input/output 0
IO1 5 3 11 Input/output 1
IO2 6 4 12 Input/output 2
IO3 7 5 14 Input/output 3
VSS 8 6 15 Supply ground
IO4 9 7 16 Input/output 4
IO5 10 8 17 Input/output 5
IO6 11 9 19 Input/output 6
IO7 12 10 20 Input/output 7
INT 13 11 1 Interrupt output (open-drain)
SCL 14 12 2 Serial clock line
SDA 15 13 4 Serial data line
VDD 16 14 5 Supply voltage
n.c. - - 3,8,13,18 Not connected
Table 6.3: Command Byte
Command Protocol Function
0 Read byte Input port register
1 Read/Write byte Output port register
2 Read/Write byte Polarity inversion register
3 Read/Write byte Configuration register