Datasheet

SMBus Protocols with PEC and without PEC
MC68HC908AP Family Data Sheet, Rev. 4
Freescale Semiconductor 243
14.8 SMBus Protocols with PEC and without PEC
Following is a description of the various MMIIC bus protocols with and without a packet error code (PEC).
14.8.1 Quick Command
Figure 14-13. Quick Command
14.8.2 Send Byte
Figure 14-14. Send Byte
14.8.3 Receive Byte
Figure 14-15. Receive Byte
START
Slave Address ACK
STOP
RW
Master to Slave
Slave to Master
Command Bit
Acknowledge
Stop ConditionStart Condition
17111
START
Slave Address ACKW
Command Code
ACK
STOP
ACK
STOP
PEC
START
Slave Address ACKW
Command Code
ACK
(a) Send Byte Protocol
(b) Send Byte Protocol with PEC
START
Slave Address ACKR
Data Byte
NAK
STOP
NAK
STOP
PEC
START
Slave Address ACKR
Data Byte
ACK
(b) Receive Byte Protocol with PEC
(a) Receive Byte Protocol