SMBus Protocols with PEC and without PEC
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
1
7
1
1
1
Master to Slave
Slave to Master
START
Slave Address RW ACK
STOP
Start Condition
Command Bit
Acknowledge
Stop Condition
Figure 14-13. Quick Command
14.8.2 Send Byte
Command Code
Command Code
START
Slave Address
W
W
ACK
ACK
ACK
ACK
STOP
(a) Send Byte Protocol
PEC
START
Slave Address
ACK
STOP
(b) Send Byte Protocol with PEC
Figure 14-14. Send Byte
14.8.3 Receive Byte
Data Byte
Data Byte
START
Slave Address
R
R
ACK
ACK
NAK
ACK
STOP
(a) Receive Byte Protocol
PEC
START
Slave Address
NAK
STOP
(b) Receive Byte Protocol with PEC
Figure 14-15. Receive Byte
MC68HC908AP Family Data Sheet, Rev. 4
Freescale Semiconductor
243
FREESCALE [ Freescale ]
