pca9500 NXP Semiconductors, pca9500 Datasheet - Page 4

• Manufacturer Part Number: pca9500
• Description: 8-bit I2c And Smbus I/o Port With 2-kbit Eeprom
• Manufacturer: NXP Semiconductors

Philips Semiconductors
FUNCTIONAL DESCRIPTION
DEVICE ADDRESSING
Following a START condition the bus master must output the address of the slave it is accessing. The address of the PCA9500 is shown in
Figure 5. Internal pullup resistors are incorporated on the hardware selectable address pins.
The last bit of the address byte defines the operation to be performed. When set to logic 1 a read is selected while a logic 0 selects a write
operation.
2004 Sep 30
8-bit I
(a) I/O EXPANDER
(b) MEMORY
2
C and SMBus I/O port with 2-kbit EEPROM
WRITE PULSE
DATA FROM
SHIFT REGISTER
POWER-ON
RESET
READ PULSE
DATA TO
SHIFT REGISTER
0
1
FIXED
SLAVE ADDRESS
0
0
a.
PROGRAMMABLE
Figure 4. Simplified schematic diagram of each I/O
A2
HARDWARE
A1
D
C
I
Figure 5. PCA9500 slave addresses
FF
S
A0
Q
R/W
D
C
I
FF
S
Q
4
1
100 A
0
FIXED
SLAVE ADDRESS
1
0
b.
A2
PROGRAMMABLE
HARDWARE
A1
A0
V
V
I/O0 TO I/O7
DD
SS
R/W
SW00546
PCA9500
Product data sheet
SW01075