Freescale Semiconductor FlexRay MFR4310 - Table 3-98. Receive Message Buffer Module Transitions; Table 3-99. Receive Message Buffer Transition Priorities

FlexRay Module (FLEXRAYV4)
MFR4310 Reference Manual, Rev. 2
164 Freescale Semiconductor
Module Transitions
The module transitions that can be triggered by the FlexRay module are described in Table 3-98. Each
transition is triggered for certain message buffers when the related condition is fulfilled.
Transition Priorities
The application can trigger only one transition at a time. There is no need to specify priorities among them.
As shown in Table 3-99, the module transitions have a higher priority than the application transitions. For
all states except the CCRx state, a module transition and the application lock/unlock transition HL/HU and
can be executed at the same time. The result state is reached by first applying the module transition and
subsequently the application transition to the intermediately reached state. For example, if the message
buffer is in the buffer subscribed state CCBs and the module triggers the slot start transition SLS at the
same time as the application locks the message buffer by the HL transition, the intermediate state is CCRx
and the resulting state is locked buffer subscribed state HLckCCRx.
3.4.6.3.2 Message Buffer Search
The FlexRay module starts a sequential search that checks all message buffers at the following protocol
related events:
• slot start, in the static frame segment
• minislot start, in the dynamic frame segment
•NIT start
The filters that are used for the search are described in Section 3.4.7.1, “Individual Message Buffer
Filtering”.
Table 3-98. Receive Message Buffer Module Transitions
Transition Condition Description
BS slot match and
CycleCounter match
B
uffer Subscribed - The message buffer filter matches next slot and cycle.
SLS slot start Slot Start - Start of Static Slot or Dynamic Slot.
SNS symbol window start or
NIT start
Symbol Window or NIT Start - Start of Symbol Window or NIT.
SSS slot start or
symbol window start or
NIT start
Sl
ot or Segment Start - Start of Static Slot, Dynamic Slot, Symbol Window, or
NIT.
SU status updated Status Updated - Slot Status field, message buffer status flags, header index
updated. Interrupt flag set.
Table 3-99. Receive Message Buffer Transition Priorities
State Priorities Description
module vs. application
Idle BS > HD Buffer Subscribed > Message Buffer Disable
HLck BS > HD Buffer Subscribed > Message Buffer Disable
CCRx SSS > HL Slot or Segment Start > Message Buffer Lock