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FlexRay Communication Controller (FlexRay)
MPC5644A Microcontroller Reference Manual, Rev. 6
Freescale Semiconductor
1595
33.6.15 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, that is, the SFFE control bit in the
Module Configuration Register (FR_MCR)
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.
33.6.15.1 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 (FR_SFIDAFVR)
and the mask is configured in
Sync Frame ID Acceptance Filter Mask Register (FR_SFIDAFMR)
. A received synchronization frame
with the frame ID FID passes the sync frame acceptance filter, if
evaluates to true.
Eqn. 33-23
Eqn. 33-24
NOTE
Sync frames are transmitted in the static segment only. Thus FID < 1023.
33.6.15.2 Sync frame rejection filtering
The synchronization frame rejection filter is a comparator. The compare value is defined by the
Frame ID Rejection Filter Register (FR_SFIDRFR)
. A received synchronization frame with the frame ID
FID passes the sync frame rejection filter if
Eqn. 33-25
Eqn. 33-26
NOTE
Sync frames are transmitted in the static segment only. Thus FID < 1023.
Table 33-125. Key slot frame type
FR_PCR11[key_slot_used_for_sync]
FR_PCR11[key_slot_used_for_startup]
Key slot frame type
0
0
normal frame
0
1
normal frame
1
1
The frame transmitted has an semantically incorrect header and will be detected as an invalid frame at the receiver.
1
0
sync frame
1
1
startup frame
FR_MCR SFFE
0
=
ID & FR_SFIDAFMR FMSK
FR_SFIDAFVR FVAL
& FR_SFIDAFMR FMSK
=
FR_MCR SFFE
0
=
FID
FR_SFIDRFR SYNFRID
Summary of Contents for MPC5644A
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Page 52: ...Introduction MPC5644A Microcontroller Reference Manual Rev 6 52 Freescale Semiconductor...
Page 56: ...Memory Map MPC5644A Microcontroller Reference Manual Rev 6 56 Freescale Semiconductor...
Page 1228: ...Decimation Filter MPC5644A Microcontroller Reference Manual Rev 6 1228 Freescale Semiconductor...
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