pca9561 NXP Semiconductors, pca9561 Datasheet - Page 4

• Manufacturer Part Number: pca9561
• Description: Quad 6-bit Multiplexed I2c Eeprom Dip Switch
• Manufacturer: NXP Semiconductors

1. All other combinations are reserved.
2. MUX_SELECT pins select between MUX_IN and EEPROM to MUX_OUT.
Philips Semiconductors
DEVICE ADDRESS
Following a START condition the bus master must output the
address of the slave it is accessing. The address of the PCA9561 is
shown in Figure 1. To conserve power, no internal pull-up resistors
are incorporated on the hardware selectable address pins and they
must be pulled HIGH or LOW.
The last bit of the slave 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.
CONTROL REGISTER DEFINITION
Following the address and acknowledge bit with logic 0 in the read/write bit, the first byte written is the command byte. If the command byte is
reserved and therefore not valid, it will not be acknowledged. Only valid command bytes will be acknowledged.
Table 1. Register Addresses
Table 2. Commands
NOTE:
2004 May 17
Quad 6-bit multiplexed I
D7
D7
0
0
0
0
1
1
1
1
1
1
1
MSB
1
D6
D6
0
0
0
0
1
1
1
1
1
1
1
0
FIXED
Figure 1. Slave address
D5
D5
0
0
0
0
1
1
1
1
1
1
1
0
1
D4
D4
0
0
0
0
1
1
1
1
1
1
1
1
PROGRAMMABLE
A1
D3
D3
0
0
0
0
1
1
1
1
1
1
1
2
C EEPROM DIP switch
A0
D2
D2
X
X
0
0
0
0
1
0
1
0
1
R/W
LSB
SW00955
D1
D1
X
X
X
0
0
1
1
1
0
0
1
D0
D0
0
1
0
1
1
0
0
1
1
0
1
4
CONTROL REGISTER
Following the successful acknowledgement of the slave address,
the bus master will send a byte to the PCA9561, which will be stored
in the control register. This register can be written and read via the
I
2
C-bus.
EEPROM 0
EEPROM 1
EEPROM 2
EEPROM 3
MUX_IN
MUX_OUT from EEPROM byte 0
MUX_OUT from EEPROM byte 1
MUX_OUT from EEPROM byte 2
MUX_OUT from EEPROM byte 3
MUX_OUT from MUX_IN
MUX_OUT from MUX_SELECT
REGISTER
D7
NAME
D6
Figure 2. Control Register
D5
Read/Write
Read/Write
Read/Write
Read/Write
Read
D4
COMMAND
TYPE
2
D3
D2
EEPROM byte 0
register
EEPROM byte 1
register
EEPROM byte 2
register
EEPROM byte 3
register
MUX_IN values
register
D1
PCA9561
FUNCTION
REGISTER
Product data sheet
D0
SW00954