SMBus Protocols with PEC and without PEC
14.8.6 Process Call
Command Code
Data Byte Low
Data Byte Low
Data Byte High
Data Byte High
STOP
START
Slave Address
Slave Address
W
R
ACK
ACK
ACK
ACK
ACK
NAK
ACK
START
(a) Process Call
Command Code
Data Byte Low
Data Byte Low
Data Byte High
Data Byte High
STOP
START
START
Slave Address
Slave Address
W
R
ACK
ACK
ACK
ACK
ACK
ACK
ACK
PEC
NAK
STOP
(b) Process Call with PEC
Figure 14-18. Process Call
14.8.7 Block Read/Write
Command Code
ACK
Data Byte N
Byte Count = N
STOP
Data Byte 1
START
Slave Address
W
ACK
ACK
ACK
ACK
ACK
ACK
ACK
Data Byte 2
(a) Block Read
Command Code
Byte Count = N
PEC
Data Byte 1
START
Slave Address
ACK
W
ACK
ACK
Data Byte 2
Data Byte N
ACK
ACK
STOP
(b) Block Read with PEC
Command Code
ACK
Byte Count = N
START
Slave Address
W
ACK
ACK
START
Data Byte N
Slave Address
R
ACK
ACK
ACK
Data Byte 1
Data Byte 2
ACK
NAK
STOP
(c) Block Write
Command Code
ACK
Byte Count = N
NAK
STOP
START
Slave Address
ACK
W
ACK
ACK
START
Slave Address
R
ACK
Data Byte 1
Data Byte 2
Data Byte N
PEC
ACK
(d) Block Write with PEC
Figure 14-19. Block Read/Write
MC68HC908AP Family Data Sheet, Rev. 4
Freescale Semiconductor
245
FREESCALE [ Freescale ]
