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Chapter 13 FlexRay Communication Controller (FLEXRAY)
MC9S12XF - Family Reference Manual, Rev.1.19
Freescale Semiconductor
569
13.6.6.3.1
Message Buffer Transitions
Application Transitions
The application transitions that can be triggered by the application using the commands described in
command is executed immediately. If the command is ignored, it must be issued again.
The enable and disable commands issued by writing 1 to the trigger bit MBCCSRn.EDT. The transition
that will be triggered by each of these command depends on the current value of the status bit
MBCCSRn.EDS. If the command triggers the disable transition HD and the message buffer is in one of
the states CCBs, HLckCCBs, or CCRx, the disable transition has no effect (command is ignored) and the
message buffer state is not changed. No notication is given to the application.
The lock and unlock commands issued by writing 1 to the trigger bit MBCCSRn.LCKT. The transition that
will be triggered by each of these commands depends on the current value of the status bit
MBCCSRn.LCKS. If the command triggers the lock transition HL while the message buffer is in the state
CCRx, the lock transition has no effect (command is ignored) and message buffer state is not changed. In
HDisLck
0
1
CFG
–
Disabled and Locked - Message Buffer under conguration.
Excluded from message buffer search.
HLck
1
MSG
–
Locked - Applications access to data, control, and status.
Included in message buffer search.
CCBs
10––
Buffer Subscribed - Message buffer subscribed for reception. Filter
matches next (slot, cycle, channel) tuple.
HLckCCBs
1
MSG
–
Locked and Buffer Subscribed - Applications access to data,
control, and status. Message buffer subscribed for reception.
CCRx
10––
Message Receive - Message data received into related shadow
buffer.
HLckCCRx
1
MSG
–
Locked and Message Receive - Applications access to data,
control, and status. Message data received into related shadow
buffer.
CCSu
1
0
–
RX
Status Update - Message buffer status update. Update of status
ags, the slot status eld, and the header index.
Table 13-100. Receive Message Buffer Application Transitions
Transition
Host Command
Condition
Description
HE
MBCCSRn.EDT:= 1
MBCCSRn.EDS = 0 Application triggers message buffer enable.
HD
MBCCSRn.EDS = 1 Application triggers message buffer disable.
HL
MBCCSRn.LCKT:= 1
MBCCSRn.LCKS = 0 Application triggers message buffer lock.
HU
MBCCSRn.LCKS = 1 Application triggers message buffer unlock.
Table 13-99. Receive Message Buffer States and Access (Sheet 2 of 2)
State
MBCCSRn
Access from
Description
EDS
LCKS
Appl.
Module