
FlexRay Communication Controller (FlexRay)
MPC5644A Microcontroller Reference Manual, Rev. 6
Freescale Semiconductor
1579
If there are multiple message buffer with highest priority, the message buffer with the lowest message
buffer number is selected. All message buffer which have the highest priority must have a consistent
channel assignment as specified in
Section 33.6.7.2, Message buffer channel assignment consistency
Depending on the message buffer channel assignment the same message buffer can be found for both
channel A and channel B. In this case, this message buffer is used as described in
”.
33.6.7.1
Message buffer cycle counter filtering
The message buffer cycle counter filter is a value-mask filter defined by the CCFE, CCFMSK, and
CCFVAL fields in the
Message Buffer Cycle Counter Filter Registers (FR_MBCCFRn)
determines a set of communication cycles in which the message buffer is considered for message reception
or message transmission. If the cycle counter filter is disabled, that is, CCFE = 0, this set of cycles consists
of all communication cycles.
If the cycle counter filter of a message buffer does not match a certain communication cycle number, this
message buffer is not considered for message transmission or reception in that communication cycle. In
case of a transmit message buffer assigned to a slot in the static segment, though, this buffer is added to
the matching message buffers to indicate the slot assignment and to trigger the null frame transmission.
The cycle counter filter of a message buffer matches the communication cycle with the number CYCCNT
if at least one of the following conditions evaluates to true:
Eqn. 33-11
Eqn. 33-12
33.6.7.2
Message buffer channel assignment consistency
The message buffer channel assignment given by the CHA and CHB bits in the
Counter Filter Registers (FR_MBCCFRn)
defines the channels on which the message buffer will receive
or transmit.
The message buffer with number
n
transmits or receives on channel A if
FR_MBCCFRn[CHA] = 1 and transmits or receives on channel B if FR_MBCCFRn[CHB] = 1.
To ensure correct message buffer operation, all message buffers assigned to the same slot and with the
same priority must have a
consistent
channel assignment. That means they must be either assigned to one
channel only, or must be assigned to
both
channels. The behavior of the message buffer search is not
Table 33-123. Message buffer search priority (dynamic segment)
Priority
MTD
LCKS
CMT
CCFM
1
1
Cycle Counter Filter Match, see
Section 33.6.7.1, Message buffer cycle counter filtering”
Description
Transition
(highest) 0
1
0
1
1
Transmit buffer, matches cycle count, not locked
and committed
MA
1
0
0
n/a
1
Receive buffer, matches cycle count, not locked
SB
(lowest) 2
0
1
n/a
1
Receive buffer, matches cycle count, locked
SB
MBCCFRn CCFE
0
=
CYCCNT & MBCCFRn CCFMSK
MBCCFRn CCFVAL
& MBCCFRn CCFMSK
=
Содержание MPC5644A
Страница 2: ...MPC5644A Microcontroller Reference Manual Rev 6 2 Freescale Semiconductor...
Страница 24: ...MPC5644A Microcontroller Reference Manual Rev 6 24 Freescale Semiconductor...
Страница 26: ...MPC5644A Microcontroller Reference Manual Rev 6 26 Freescale Semiconductor...
Страница 52: ...Introduction MPC5644A Microcontroller Reference Manual Rev 6 52 Freescale Semiconductor...
Страница 56: ...Memory Map MPC5644A Microcontroller Reference Manual Rev 6 56 Freescale Semiconductor...
Страница 130: ...Device Performance Optimization MPC5644A Microcontroller Reference Manual Rev 6 130 Freescale Semiconductor...
Страница 204: ...Multi Layer AHB Crossbar Switch XBAR MPC5644A Microcontroller Reference Manual Rev 6 204 Freescale Semiconductor...
Страница 212: ...Peripheral Bridge PBRIDGE MPC5644A Microcontroller Reference Manual Rev 6 212 Freescale Semiconductor...
Страница 558: ...System Integration Unit SIU MPC5644A Microcontroller Reference Manual Rev 6 558 Freescale Semiconductor...
Страница 582: ...Frequency modulated phase locked loop FMPLL MPC5644A Microcontroller Reference Manual Rev 6 582 Freescale Semiconductor...
Страница 766: ...Enhanced Time Processing Unit eTPU2 MPC5644A Microcontroller Reference Manual Rev 6 766 Freescale Semiconductor...
Страница 1228: ...Decimation Filter MPC5644A Microcontroller Reference Manual Rev 6 1228 Freescale Semiconductor...
Страница 1236: ...System Information Module and Trim SIM MPC5644A Microcontroller Reference Manual Rev 6 1236 Freescale Semiconductor...
Страница 1250: ...Cyclic Redundancy Checker CRC Unit MPC5644A Microcontroller Reference Manual Rev 6 1250 Freescale Semiconductor...
Страница 1336: ...Deserial Serial Peripheral Interface DSPI MPC5644A Microcontroller Reference Manual Rev 6 1336 Freescale Semiconductor...
Страница 1388: ...Enhanced Serial Communication Interface ESCI MPC5644A Microcontroller Reference Manual Rev 6 1388 Freescale Semiconductor...
Страница 1440: ...FlexCAN Module MPC5644A Microcontroller Reference Manual Rev 6 1440 Freescale Semiconductor...
Страница 1624: ...FlexRay Communication Controller FlexRay MPC5644A Microcontroller Reference Manual Rev 6 1624 Freescale Semiconductor...
Страница 1670: ...JTAG Controller JTAGC MPC5644A Microcontroller Reference Manual Rev 6 1670 Freescale Semiconductor...
Страница 1692: ...Nexus Port Controller NPC MPC5644A Microcontroller Reference Manual Rev 6 1692 Freescale Semiconductor...
Страница 1701: ...Development Trigger Semaphore DTS MPC5644A Microcontroller Reference Manual Rev 6 Freescale Semiconductor 1701...
Страница 1702: ...Development Trigger Semaphore DTS MPC5644A Microcontroller Reference Manual Rev 6 1702 Freescale Semiconductor...