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Chapter 13 FlexRay Communication Controller (FLEXRAY)
MC9S12XF - Family Reference Manual, Rev.1.19
Freescale Semiconductor
571
With the start of the next static or dynamic slot the module trigger the slot start transition SLS. This
changes the state of the subscribed receive message buffers from either CCBs to CCRx or from HLckCCBs
to HLckCCRx, respectively.
During the reception slot, the received frame data are written into the shadow buffers. For details on receive
receive message buffers that are the CCRx or HLckCCRx are not modied in the reception slot.
13.6.6.3.3
Message Buffer Status Update
With the start of the next static or dynamic slot or with the start of the symbol window or NIT, the module
trigger the slot or segment start transition SSS. This transition changes the state of the receiving receive
message buffers from either CCRx to CCSu or from HLckCCRx to HLck, respectively.
If a message buffer was in the locked state HLckCCRx, no update will be performed. The received data
are lost. This is indicated by setting the Frame Lost Channel A/B Error Flag FRLA_EF/FRLB_EF in the
If a message buffer was in the CCRx state it is now in the CCSu state. After the evaluation of the slot status
provided by the PE the message buffer is updated. The message buffer update depends on the slot status
bits and the segment the message buffer is assigned to. This is described in
Table 13-103.Table 13-103. Receive Message Buffer Update
vSS!ValidFrame
vRF!Header!NFIndicator
Update description
11
Valid non-null frame received.
- Message Buffer Data Field updated.
- Frame Header Field updated.
- Slot Status Field updated.
- DUP:= 1
- DVAL:= 1
- MBIF:= 1
10
Valid null frame received.
- Message Buffer Data Field not updated.
- Frame Header Field not updated.
- Slot Status Field updated.
- DUP:= 0
- DVAL not changed
- MBIF:= 1
0x
No valid frame received.
- Message Buffer Data Field not updated.
- Frame Header Field not updated.
- Slot Status Field updated.
- DUP:= 0
- DVAL not changed.
- MBIF:= 1, if the slot was not an empty dynamic slot.
Note: An empty dynamic slot is indicated by the following frame and slot
status bit values:
vSS!ValidFrame = 0 and vSS!SyntaxError = 0 and
vSS!ContentError = 0 and vSS!BViolation = 0.