FlexRay Communication Controller (FLEXRAY)
22-104
Freescale Semiconductor
PXR40 Microcontroller Reference Manual, Rev. 1
Figure 22-125. Null Frame Transmission from HLck state with unlock
Since the null frame transmission will not use the message buffer data, the application can lock/unlock the
message buffer during null frame transmission. A transmit message buffer timing and state change
diagram for null frame transmission for this case is given in
Figure 22-126. Null Frame Transmission from Idle state with locking
22.6.6.2.7
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 controller updates the slot status field of the message
buffer and triggers the status updated transition SU. With the SU transition, the controller sets the message
buffer interrupt flag MBCCSn[MBIF] to indicate the successful message transmission.
Depending on the transmission mode flag MBCCFRn[MTM], the controller 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 controller will
not clear the MBCCSRn[CMT] flag at the end of transmission and will set the valid flag
MBCCSRn[DVAL] to indicate that the message will be transmitted again.
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Summary of Contents for PXR4030
Page 1: ...PXR40 Microcontroller Reference Manual Devices Supported PXR4030 PXR4040 PXR40RM Rev 1 06 2011...
Page 30: ...PXR40 Microcontroller Reference Manual Rev 1 Freescale Semiconductor xxx...
Page 40: ...PXR40 Microcontroller Reference Manual Rev 1 xl Freescale Semiconductor...
Page 66: ...Memory Map PXR40 Microcontroller Reference Manual Rev 1 2 4 Freescale Semiconductor...
Page 120: ...Signal Descriptions 3 54 Freescale Semiconductor PXR40 Microcontroller Reference Manual Rev 1...
Page 860: ...FlexCAN Module 24 50 Freescale Semiconductor PXR40 Microcontroller Reference Manual Rev 1...
Page 1167: ...Decimation Filter Freescale Semiconductor 28 53 PXR40 Microcontroller Reference Manual Rev 1...
Page 1168: ...Decimation Filter 28 54 Freescale Semiconductor PXR40 Microcontroller Reference Manual Rev 1...