BU8272GUW ROHM Co. Ltd., BU8272GUW Datasheet - Page 14

• Manufacturer Part Number: BU8272GUW
• Description: Gpio Expander Ic
• Manufacturer: ROHM Co. Ltd.

© 2009 ROHM Co., Ltd. All rights reserved.
BU8272GUW
www.rohm.com
2.2 Read From GPIO Port
After slave address and R/W bit is written, the GPIO ports value will be read into the GPIO registers. (refer to section 8.1.6
for 2-wire reading protocol.) The data fixed between tow consecutive acknowledges will be transferred to the Master.
2.3 Interrupt Valid/Reset
The transition of each GPIO port de-asserts the interrupt signal (INT), generates the interrupt signal by asserting the INT
after each acknowledge signaling.
Either a “High-Active” or a “Low-Active” interrupt signaling can be defined by changing the INTSEL register value
beforehand.
GPIO
GPIO
SDA
SCL
SDA
SCL
INT
S
Start Condition
S
Start Condition
X
X
1
1
X
X
Data1
2
2
X
X
t
3
3
IV
Data0
X
X
4
4
X
X
5
5
X
X
t
DS
6
6
X
X
7
7
Read
Read
Fig. 16 Read from GPIO port
1
1
8
Fig. 17 Interrupt Valid/Reset
8
Ack
Ack
9
9
Data2
Acknowledge From Slave
Acknowledge From Slave
MSB
MSB
Data1
t
IR
14/17
Data2
Data0
LSB
LSB
Ack
Ack
MSB
MSB
Acknowledge From Master
Acknowledge From Master
Data3
t
DH
No Acknowledge From Master
No Acknowledge From Master
Data3
Data1
Data2
LSB
LSB
Technical Note
2009.09 - Rev.A
NA
NA
P
Stop Condition
P
Stop Condition