PXS20RM Datasheet, PDF (837/1368 Pages) Freescale Semiconductor, Inc – PXS20 Microcontroller

FlexRay Communication Controller
Table 26-111. Receive Message Buffer States and Access (continued)
State
HDisLck
HLck
CCBs
HLckCCBs
CCRx
HLckCCRx
CCSu
FR_MBCCSRn
EDS LCKS
0
1
1
1
1
0
1
1
1
0
1
1
1
0
Access from
Appl.
Modul
e
Description
CFG
MSG
–
MSG
–
MSG
–
– Disabled and Locked - Message Buffer under configuration.
Excluded from message buffer search.
– Locked - Applications access to data, control, and status.
Included in message buffer search.
– Buffer Subscribed - Message buffer subscribed for reception.
Filter matches next (slot, cycle, channel) tuple.
– Locked and Buffer Subscribed - Applications access to
data, control, and status. Message buffer subscribed for
reception.
– Message Receive - Message data received into related
shadow buffer.
– Locked and Message Receive - Applications access to data,
control, and status. Message data received into related
shadow buffer.
RX Status Update - Message buffer status update. Update of
status flags, the slot status field, and the header index.
26.6.6.3.1 Message Buffer Transitions
Application Transitions
The application transitions that can be triggered by the application using the commands described in
Table 26-112. The application issues the commands by writing to the Message Buffer Configuration,
Control, Status Registers (FR_MBCCSRn). Only one command can be issued with one write access. Each
command is executed immediately. If the command is ignored, it must be issued again.
Message Buffer Enable and Disable
The enable and disable commands issued by writing 1 to the trigger bit FR_MBCCSRn[EDT]. The
transition that will be triggered by each of these command depends on the current value of the status bit
FR_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 notification is given to the application.If the communication
controller is started as a non-coldstart node and configured and enabled message buffers in the POC config
state for Slot 1, then the message buffer CAN NOT be disabled in the INTEGRATION_LISTEN state by
directly writing '1' to the EDT bit. To facilitate this, a FREEZE command needs to be issued just before
running the message buffer disable for slot 1. This should enable the message buffer disable during the
LISTEN states.
Message Buffer Lock and Unlock
The lock and unlock commands issued by writing 1 to the trigger bit FR_MBCCSRn[LCKT]. The
transition that will be triggered by each of these commands depends on the current value of the status bit
FR_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
Freescale Semiconductor
PXS20 Microcontroller Reference Manual, Rev. 1
26-125