FlexRay Communication Controller (FLEXRAY)
MPC5510 Microcontroller Family Reference Manual, Rev. 1
30-134
Freescale Semiconductor
Preliminary
PCR11.key_slot_used_for_startup is set, or if a transmit message buffer with MBFIDRn.FID ==
PCR18.key_slot_id is configured and enabled, a Null Frame or Data Frame will be transmitted in the slot
with slot number PCR18.key_slot_id. The header CRC for this frame is taken from
PCR12.key_slot_header_crc, the settings of the sync and startup frame indicators are taken from
PCR11.key_slot_used_for_sync and PCR11.key_slot_used_for_startup. A data frame will be transmitted
if the message buffer is unlocked and committed and the cycle counter filter matches the current cycle.
30.6.15 Sync Frame Filtering
Each received synchronization frame must pass the Sync Frame Acceptance Filter and the Sync Frame
Rejection Filter before it is considered for clock synchronization. If the synchronization frame filtering is
globally disabled, i.e. the SFFE control bit in the
Module Configuration Register (MCR)
is cleared, all
received synchronization frames are considered for clock synchronization. If a received synchronization
frame did not pass at least one of the two filters, this frame is processed as a normal frame and is not
considered for clock synchronization.
30.6.15.1 Sync Frame Acceptance Filtering
The synchronization frame acceptance filter is implemented as a value-mask filter. The value is configured
in the
Sync Frame ID Acceptance Filter Value Register (SFIDAFVR)
and the mask is configured in the
Sync Frame ID Acceptance Filter Mask Register (SFIDAFMR)
. A received synchronization frame with
the frame ID FID passes the sync frame acceptance filter, if
true.
Eqn. 30-21
Eqn. 30-22
NOTE
Sync frames are transmitted in the static segment only. Thus FID <= 1023.
30.6.15.2 Sync Frame Rejection Filtering
The synchronization frame rejection filter is a comparator. The compare value is defined by the
Frame ID Rejection Filter Register (SFIDRFR)
. A received synchronization frame with the frame ID FID
passes the sync frame rejection filter if
evaluates to true.
Eqn. 30-23
Eqn. 30-24
NOTE
Sync frames are transmitted in the static segment only. Thus FID <= 1023.
MCR SFFE
[
]
0
=
FID
9:0
[
]
SFIDAFMR FMSK
9:0
[
]
[
]
∧
SFIDAFVR FVAL
9:0
[
]
[
]
SFIDAFMR FMSK
9:0
[
]
[
∧
=
MCR SFFE
[
]
0
=
FID
9:0
[
]
SFIDRFR SYNFRID
9:0
[
]
[
]
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