9-16
Intel® PXA255 Processor
Developer’s Manual
I
2
C Bus Interface Unit
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.
Figure 9-14
shows a general call address transaction. The least significant bit of
the second byte, called B, defines the transaction.
Table 9-7
shows the valid values and definitions
when B=0.
Figure 9-11. Master-Transmitter Write to Slave-Receiver
Figure 9-12. Master-Receiver Read to Slave-Transmitter
Figure 9-13. Master-Receiver Read to Slave-Transmitter, Repeated START, Master-Transmitter
Write to Slave-Receiver
Master to Slave
Slave to Master
START
Slave Address
R/nW
0
ACK
Data
Byte
ACK
Data
Byte
STOP
N Bytes + ACK
Write
ACK
First Byte
Master to Slave
Slave to Master
START
Slave Address
R/nW
1
ACK
Data
Byte
ACK
Data
Byte
STOP
N Bytes + ACK
Read
NAK
Default
Slave-Receive
Mode
First Byte
START
Slave
R/nW
1
ACK
Data
Byte ACK
Data
Byte
N Bytes + ACK
Read
ACK SR
Slave
R/nW
0
ACK
Data
Byte ACK
Data
Byte
STOP
N Bytes + ACK
Write
ACK
Address
Address
Master to Slave
Slave to Master
Repeated
START
Data Chaining
Summary of Contents for PXA255
Page 1: ...Intel PXA255 Processor Developer s Manual January 2004 Order Number 278693 002 ...
Page 24: ...xxiv Intel PXA255 Processor Developer s Manual Contents ...
Page 30: ...1 6 Intel PXA255 Processor Developer s Manual Introduction ...
Page 310: ...7 46 Intel PXA255 Processor Developer s Manual LCD Controller ...
Page 330: ...8 20 Intel PXA255 Processor Developer s Manual Synchronous Serial Port Controller ...
Page 358: ...9 28 Intel PXA255 Processor Developer s Manual I2 C Bus Interface Unit ...
Page 488: ...13 36 Intel PXA255 Processor Developer s Manual AC 97 Controller Unit ...
Page 572: ...16 30 Intel PXA255 Processor Developer s Manual Network SSP Serial Port ...
Page 599: ...Intel PXA255 Processor Developer s Manual 17 27 Hardware UART ...
Page 600: ......