![Freescale Semiconductor FlexRay MFR4310 Reference Manual Download Page 160](http://html1.mh-extra.com/html/freescale-semiconductor/flexray-mfr4310/flexray-mfr4310_reference-manual_2330597160.webp)
FlexRay Module (FLEXRAYV4)
MFR4310 Reference Manual, Rev. 2
160
Freescale Semiconductor
Figure 3-116. Null Frame Transmission from Idle State with locking
3.4.6.2.7
Message Buffer Status Update
After the end of each slot, the PE generates the slot status vector. Depending on the this status, the
transmitted frame type, and the amount of transmitted data, the message buffer status is updated.
Message Buffer Status Update after Complete Message Transmission
The term complete message transmission refers to the fact that all payload data stored in the message
buffer were send to FlexRay bus. In this case, the FlexRay module updates the slot status field of the
message buffer and triggers the status updated transition
SU
. With the
SU
transition, the FlexRay module
sets the message buffer interrupt flag MBCCSn.MBIF to indicate the successful message transmission.
Depending on the transmission mode flag MBCCFRn.MTM, the FlexRay module changes the commit
flag MBCCSRn.CMT and the valid flag MBCCSRn.DVAL. If the MBCCFRn.MTM flag is negated, the
message buffer is in the
event transmission mode.
In this case, each committed message is transmitted only
once. The commit flag MBCCSRn.CMT is cleared with the
SU
transition. If the MBCCFRn.MTM flag is
asserted, the message buffer is in the
state transmission mode
. In this case, each committed message is
transmitted as long as the application provides new data or locks the message buffers. The FlexRay module
does not clear the MBCCSRn.CMT flag at the end of transmission and sets the valid flag
MBCCSRn.DVAL to indicate the message is transmitted again.
Message Buffer Status Update after Incomplete Message Transmission
The term incomplete message transmission refers to the fact that not all payload data that should be
transmitted were send to FlexRay bus. This may be caused by the following regular conditions in the
dynamic segment:
1. The transmission slot starts in a minislot with a minislot number greater than
pLatestTx
.
2. The transmission slot did not exist in the dynamic segment at all.
Additionally, an incomplete message transmission can be caused by internal communication errors. If
those error occur, the Protocol Engine Communication Failure Interrupt Flag PECF_IF is set in the
Protocol Interrupt Flag Register 1 (PIFR1)
.
In any of these two cases, the status of the message buffer is not changed at all with the SU transition. The
slot status field is not updated, the status and control flags are not changed, and the interrupt flag is not set.
search[s+1]
MT
st
art
MT s
tar
t
SA
slot s
ST
SS
slot s+1
Idle
MT s
tar
t
HLck
slot s+2
slot
st
art
slot
st
art
slot
st
art
null frame transmit
HL
CCSa CCNf
HLckCCNf
Summary of Contents for FlexRay MFR4310
Page 2: ......
Page 3: ...MFR4310 Reference Manual MFR4310RM Rev 2 03 2008...
Page 6: ...MFR4310 Reference Manual Rev 2 6 Freescale Semiconductor...
Page 12: ...MFR4310 Reference Manual Rev 2 12 Freescale Semiconductor Section Number Title Page...
Page 24: ...MFR4310 Reference Manual Rev 2 24 Freescale Semiconductor Table Number Title Page...
Page 28: ...Introduction MFR4310 Reference Manual Rev 2 28 Freescale Semiconductor...
Page 58: ...Device Overview MFR4310 Reference Manual Rev 2 58 Freescale Semiconductor...
Page 234: ...Clocks and Reset Generator CRG MFR4310 Reference Manual Rev 2 234 Freescale Semiconductor...
Page 260: ...Package Information MFR4310 Reference Manual Rev 2 260 Freescale Semiconductor...
Page 267: ......