9-14 Intel® PXA255 Processor Developer’s Manual
I2C Bus Interface Unit
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9.4.6 Slave Operations
Table 9 -6 describes how the I2C unit operates as a slave device.
Figure 9-8. Master-Receiver Read from Slav e-Transmitter
Figure 9-9. Master-Receiver Read from Slav e-Transmitter / Repeated Start / Master-
Transmitter Write to Slave-Receiver
Figure 9-10. A Complete Data Transfer
Master to Slave Slave to Master
START Slave Address R/nW
1ACK Data
Byte ACK Data
Byte STOP
N Bytes + ACK
ACK
Default
Slave-Receive
Mode
First Byte Read
START Slave R/nW
1ACK Data
Byte ACK Data
Byte
N Bytes + ACK
Read
ACK Sr Slave R/nW
0ACK Data
Byte ACK Data
Byte STOP
N Bytes + ACK
Write
ACK
Address Address
Master to Slave Slave to Master
Repeated
Start
Data Chaining
SDA
SCL
Start
Condition Address R/nW ACK Data ACK Data
1-7 8 9 8 989
1-7 1-7
ACK Stop
Condition