MC908QL4 FREESCALE [Freescale Semiconductor, Inc], MC908QL4 Datasheet - Page 156

• Manufacturer Part Number: MC908QL4
• Description: M68HC08 Microcontrollers
• Manufacturer: FREESCALE [Freescale Semiconductor, Inc]

Slave LIN Interface Controller (SLIC) Module
The SLIC transmit go (TXGO) bit should be 0 for command frames, indicating to the SLIC that data is
coming from the master. The checksum mode control (CHKMOD) bit allows the user to select which
method of checksum calculation is desired for this message frame. The LIN 1.3 checksum does not
include the identifier byte in the calculation, while the SAE version does include this byte. Because the
identifier is already received by the SLIC by this time, the default is to include it in the calculation. If a LIN
1.3 checksum is desired, a 1 in CHKMOD will reset the checksum circuitry to begin calculating the
156
RECEIVE BUFFER OVERRUN
PROCESS ERROR CODE:
BYTE FRAMING ERROR
CHECKSUM-ERROR
RETURN TO IDLE
NO-BUS-ACTIVITY
EXIT ISR
Figure 14-16. Handling Command Messages (Data Receive)
Y
WRITE SLCDLC FOR THIS ID
0n00 0xxx
(TXGO = 0)
(CHKMOD = n)
COMMAND MESSAGE
EXTENDED FRAME
EMPTY RX BUFFER
ERROR CODE
READ SLCSV
CLEAR SLCF
INTERRUPT
PROCESS
EXIT ISR
VALID ID
N
Y
N
?
?
?
MC68HC908QL4 Data Sheet, Rev. 7
N
Y
1. EMPTY RX BUFFER
2. DECREMENT SW BYTE COUNT BY 8
N
INITIALIZE SW BYTE COUNT
WRITE SLCDLC FOR THIS ID
0nxx xxxx
(TXGO = 0)
(CHKMOD = n)
REQUEST MESSAGE
(SW BYTE COUNT £8)
PROCESS
ERROR CODE
LAST FRAME
READ SLCSV
CLEAR SLCF
INTERRUPT
EXIT ISR
N
Y
?
?
Y
Freescale Semiconductor
RECEIVE BUFFER OVERRUN
PROCESS ERROR CODE:
BYTE FRAMING ERROR
NO-BUS-ACTIVITY
RETURN TO IDLE
EXIT ISR