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MFR4200 FlexRay Communication Controller
MFR4200 Data Sheet, Rev. 0
156
Freescale Semiconductor
Transmit message buffer:
The content of the buffer is transmitted only on the channels specified in the channel filtering field when
the cycle counter filtering and frame ID filtering criteria are also met.
Receive FIFO:
Those bits have no meaning for the receive FIFO (refer to
Section 3.6, “Receive FIFO Function
” for more
information about FIFO filters)
3.4.1.7
CCFE — Cycle Counter Filtering Enable Bit
The host controls the cycle counter filtering (refer to
Section 3.2.3.8.4, “Cycle Counter Filter n Register,
n = [0:58] (CCFnR)
”) of a buffer by the cycle counter filtering enable bit.
1 – Cycle counter filtering is enabled.
0 – Cycle counter filtering is not performed.
3.4.1.8
DATUPD — Data Updated
DATUPD indicates if the frame data was or was not updated during the last matching slot/cycle/channel
triple in the static segment according to the filter. The CC updates the DATUPD bit after every static slot
assigned to this buffer. The host may reset this bit during the configuration state by writing a “0” to the bit.
Note that DATUPD is not reset by empty minislots in the dynamic segment. It is set, however, when a
semantically valid frame is received in the dynamic segment.
1 – A semantically valid (non null) frame was received during the last slot with a matching
slot/cycle/channel triple.
0 – Either a frame that was not semantically valid or a null frame was received during the last slot with a
matching slot/cycle/channel triple.
3.4.1.9
BT — Buffer Type
The host can configure every buffer of the CC as a single transmit message buffer or as a double message
buffer. The handling and the operations for buffers with different types are specified in
Section 3.5,
“Message Buffer Handling and Operations
”.
0 – Single transmit message buffer.
Table 3-15. Channel Filtering Configuration
ChA
ChB
Transmit message buffer
Transmit frame
Receive message buffer
Store semantically valid received frame
1
1
on both channels
ignore frame
1
0
on channel A
received on channel A
0
1
on channel B
received on channel B
0
0
no transmission
ignore frame