pca9506 NXP Semiconductors, pca9506 Datasheet - Page 17

• Manufacturer Part Number: pca9506
• Description: 40-bit I2c-bus I/o Port With Reset, Oe, And Int
• Manufacturer: NXP Semiconductors

Fig 13. Write to the I/O Configuration, Polarity Inversion or Mask Interrupt registers
Fig 14. Read from Input Port, Output Port, I/O Configuration, Polarity Inversion or Mask Interrupt registers
SDA
The programming becomes effective at the acknowledge.
Less than 5 bytes can be programmed by using this scheme. D5, D4, D3, D2, D1, D0 refers to the first register to be programmed.
If more than 5 bytes are written, previous data are overwritten (the sixth Configuration register will roll over to the first addressed Configuration register, the sixth
Polarity Inversion register will roll over to the first addressed Polarity Inversion register and the sixth Mask Interrupt register will roll over to the first addressed Mask
Interrupt register).
If AI = 0, the same register is read during the whole sequence.
If AI = 1, the register value is incremented after each read. When the last register bank is read, it rolls over to the first byte of the category (see category definition in
Section 7.2 “Command
The INT signal is released only when the last register containing an input that changed has been read. For example, when IO2_4 and IO4_7 change at the same time
and an Input Port register’s read sequence is initiated, starting with IP0, INT is released after IP4 is read (and not after IP2 is read).
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S
START condition
SDA
0 1 0 0 A2 A1 A0 0
S
START condition
slave address
0 1 0 0
register determined by D[5:0]
slave address
data from register
first byte
register”).
acknowledge
DATA
A2 A1 A0
from slave
R/W
acknowledge
from slave
A
R/W
AI = 1
0
1 0 D5 D4 D3 D2 D1 D0
A
acknowledge from master
A
command register
AI = 1
1 0 D5 D4 D3 D2 D1 D0
command register
data from register
second byte
DATA
D[5:0] = 01 0000 for Polarity Inversion register programming bank 0
D[5:0] = 01 1000 for Configuration register programming bank 0
D[5:0] = 10 0000 for Mask Interrupt register programming bank 0
D[5:0] = 00 0000 for Input Port register bank 0
D[5:0] = 00 1000 for Output Port register bank 0
D[5:0] = 01 0000 for Polarity Inversion register bank 0
D[5:0] = 01 1000 for Configuration register bank 0
D[5:0] = 10 0000 for Mask Interrupt register bank 0
A
acknowledge
from slave
DATA BANK 0
A
acknowledge from slave
acknowledge from master
A
Sr
repeated START condition
0 1 0 0
slave address
A
acknowledge
from slave
DATA BANK 1
A2 A1 A0
R/W
1
A
acknowledge
from slave
data from register
A
acknowledge from slave
DATA BANK 2
At this moment master-transmitter becomes master-receiver,
and slave-receiver becomes slave-transmitter.
last byte
DATA
(cont.)
A
acknowledge
from slave
DATA BANK 3
no acknowledge from master
A
P
STOP
condition
acknowledge
from slave
A
DATA BANK 4
002aab499
acknowledge
from slave
condition
002aab498
STOP
A
P