FlexRay Module (FLEXRAYV2)
MFR4300 Data Sheet, Rev. 1
156
Freescale Semiconductor
Module Transitions
The module transitions that can be triggered by the FlexRay module are described in
Table 3-93
. Each
transition will be 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 the first part of
Table 3-94
, the module transitions have a higher priority than the application
transitions. For all states except the
CCMa
state, both a lock/unlock transition
HL/HD
and a module
transition can be executed at the same time. The result state is reached by first applying the application
transition and subsequently the module transition to the intermediately reached state. For example, if the
message buffer is in the
HLck
state and the application unlocks the message buffer by the
HU
transition
and the module triggers the slot assigned transition
SA
, the intermediate state is
Idle
and the resulting state
is
CCSa
.
The priorities among the module transitions is given in the second part of
Table 3-94
.
HL
HU
MBCCSRn.LCKT:= 1
MBCCSRn.LCKS = 0 Application triggers message buffer lock.
MBCCSRn.LCKS = 1 Application triggers message buffer unlock.
Table 3-93. Single Transmit Message Buffer Module Transitions
Transition
Condition
Description
SA
slot match and
static slot
slot match and
CycleCounter match
slot start and
MBCCSRn.CMT = ‘1’
status updated
Slot Assigned
- Message buffer is assigned to next static slot.
MA
Message Available
- Message buffer is assigned to next slot and cycle counter
filter matches.
Transmission Slot Start
- Slot Start and commit bit CMT is set.
In case of a dynamic slot, pLatestTx is not exceeded.
Status Updated
- Slot Status field and message buffer status flags updated.
Interrupt flag set.
Static Slot Start
- Start of static slot.
TX
SU
STS
static slot start
DSS
dynamic slot start or
symbol window start or
NIT start
slot start or
symbol window start or
NIT start
Dynamic Slot or Segment Start.
- Start of dynamic slot or symbol window or
NIT.
SSS
Slot or Segment Start
- Start of static slot or dynamic slot or symbol window or
NIT.
Table 3-94. Single Transmit Message Buffer Transition Priorities
State
Priorities
Description
module vs. application
Idle, HLck
SA > HD
MA > HD
TX > HL
Slot Assigned > Message Buffer Disable
Message Available > Message Buffer Disable
Transmission Start > Message Buffer Lock
CCMa
Table 3-92. Single Transmit Message Buffer Application Transitions
Transition
Command
Condition
Description