General Call Address; Master-Transmitter Write To Slave-Receiver; Master-Receiver Read To Slave-Transmitter; Master-Receiver Read To Slave-Transmitter, Repeated Start, Master Transmitter Write To Slave-Receiver - Intel PXA255 Developer's Manual

2
I C Bus Interface Unit
Figure 9-11. Master-Transmitter Write to Slave-Receiver
Master to Slave
Figure 9-12. Master-Receiver Read to Slave-Transmitter
START
Master to Slave
Figure 9-13. Master-Receiver Read to Slave-Transmitter, Repeated START, Master-Transmitter
Write to Slave-Receiver
START
Master to Slave
9.4.8

General Call Address

A general call address is a transaction with a slave address of 0x00. When a device requires the
data from a general call address, it acknowledges the transaction and stays in slave-receiver mode.
Otherwise, the device ignores the general call address. The other bytes in a general call transaction
are acknowledged by every device that uses it on the bus. Devices that do not use these bytes must
not send an ACK. The meaning of a general call address is defined in the second byte sent by the
master-transmitter.
the second byte, called B, defines the transaction.
when B=0.
9-16
START Slave Address
First Byte
Slave to Master
R/nW
Slave Address
First Byte
Slave to Master
R/nW Data
Slave
ACK Byte ACK
Address
1
Read N Bytes + ACK
Slave to Master
Figure 9-14 shows a general call address transaction. The least significant bit of
R/nW Data
ACK
0 Byte
Write N Bytes + ACK
Data
ACK
1 Byte
Read N Bytes + ACK
Default
Slave-Receive
Mode
Data
Slave
ACK SR
Address
Byte
Repeated
START
Data Chaining
Table 9-7 shows the valid values and definitions
Intel® PXA255 Processor Developer's Manual
Data
ACK ACK STOP
Byte
Data
ACK NAK STOP
Byte
R/nW Data Data
ACK Byte ACK ACK
0 Byte
Write N Bytes + ACK
STOP