NXP Semiconductors PXN2020, Reference Manual, Page: 733 / 1376

FlexRay Communication Controller (FlexRAY)
PXN20 Microcontroller Reference Manual, Rev. 1
Freescale Semiconductor 26-119
Module Transitions
The module transitions that can be triggered by the controller are described in Table 26-110 . The
transitions C1 and C2 apply to both sides of the message buffer and are applied at the same time. All other
controller transitions apply to the transmit side only.
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 26-111 , the module transitions have a higher priority than the
application transitions. The priorities among the controller transitions and the related states are given in
the second part of
Table 26-111 . These priorities apply only to the transmit side. The internal message
transmit start transition IS has tho lowest priority.
Table 26-110. Double Transmit Message Buffer Module Transitions
Transition Condition Description
common transitions
IS
see Section 26.6.6.4.5,
Internal Message Transfer
Internal Message Transfer Start - Start transfer of message data from commit side
to transmit side.
IE Internal Message Transfer End - Stop transfer of message data from commit side
to transmit side.
Note: The internal message transfer is stopped before the slot or segment start.
transmit side specific transitions
SA slot match and
static slot
Slot Assigned - Message buffer is assigned to next static slot.
MA slot match and
CycleCounter match
Message Available - Message buffer is assigned to next slot and cycle counter
filter matches.
TX slot start and
MBCCSR(2n + 1)[CMT] = 1
Transmission Slot Start - Slot Start and commit bit CMT is set.
In case of a dynamic slot, pLatestTx is not exceeded.
SU status updated Status Updated - Slot Status field and message buffer status flags updated.
Interrupt flag set.
STS static slot start Static Slot Start - Start of static slot.
DSS
dynamic 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 start or
symbol window start or
NIT start
Slot or Segment Start - Start of static slot or dynamic slot or symbol window or
NIT.
Table 26-111. Double Transmit Message Buffer Transition Priorities
State Priority Description
module vs. application
Idle IS > HD
IS > HL
Internal Message Transfer Start > Message Buffer Disable
Internal Message Transfer Start > Message Buffer Lock
module internal
Idle MA > SA Message Available > Slot Assigned