pca9672 NXP Semiconductors, pca9672 Datasheet - Page 8

• Manufacturer Part Number: pca9672
• Description: Pca9672 Remote 8-bit I/o Expander For Fm I?c-bus With Interrupt And Reset
• Manufacturer: NXP Semiconductors

NXP Semiconductors
PCA9672_2
Product data sheet
7.2.2 Device ID (PCA9672 ID field)
The Device ID field is a 3-byte read-only (24 bits) word giving the following information:
The Device ID is read-only, hardwired in the device and can be accessed as follows:
1. START command
2. The master sends the Reserved Device ID I
3. The master sends the I
4. The master sends a Re-START command.
5. The master sends the Reserved Device ID I
6. The device ID read can be done, starting with the 8 manufacturer bits (first byte +
7. The master ends the reading sequence by NACKing the last byte, thus resetting the
Fig 10. PCA9672 ID
•
•
•
8 bits with the manufacturer name, unique per manufacturer (for example, NXP).
13 bits with the part identification, assigned by manufacturer, the 7 MSBs with the
category ID and the 6 LSBs with the feature ID (for example, for example PCA9672
8-bit quasi-output I/O expander).
3 bits with the die revision, assigned by manufacturer (for example, Rev X).
bit set to 0 (write).
The LSB is a ‘Don’t care’ value. Only one device must acknowledge this byte (the one
that has the I
Remark: A STOP command followed by a START command will reset the slave state
machine and the Device ID read cannot be performed.
Remark: A STOP command or a Re-START command followed by an access to
another slave device will reset the slave state machine and the Device ID read cannot
be performed.
bit set to 1 (read).
4 MSB of the second byte), followed by the 13 part identification bits and then the
3 die revision bits (3 LSB of the third byte).
slave device state machine and allowing the master to send the STOP command.
Remark: The reading of the Device ID can be stopped anytime by sending a NACK
command.
Remark: If the master continues to ACK the bytes after the third byte, the PCA9672
rolls back to the first byte and keeps sending the Device ID sequence until a NACK
has been detected.
For the PCA9672, the Device ID is as shown in
part identification
2
Remote 8-bit I/O expander for Fm+ I
C-bus slave address).
Rev. 02 — 6 July 2007
2
0
C-bus slave address of the slave device it needs to identify.
0
category identification
manufacturer
0
0
0
0
0
2
2
C-bus address ‘1111 100’ with the R/W
C-bus address ‘1111 100’ with the R/W
0
1
Figure
0
0
2
C-bus with interrupt and reset
feature identification
0
0
revision
10.
0
0
0
0
0
002aac326
0
1
0
PCA9672
© NXP B.V. 2007. All rights reserved.
0
1
0
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