PXS20RM Datasheet, PDF (868/1368 Pages) Freescale Semiconductor, Inc – PXS20 Microcontroller

FlexRay Communication Controller
Table 26-125. Key Slot Frame Type
FR_PCR11[key_slot_used_for_syn FR_PCR11[key_slot_used_for_star
c]
tup]
key slot frame type
0
0
normal frame
0
1
normal frame¹
1
0
sync frame
1
1
startup frame
NOTES:
1 _{The frame transmitted has an semantically incorrect header and will be detected as an invalid frame at the receiver.}
26.6.15 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 (FR_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.
26.6.15.1 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
the 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 Equation 26-24 or
Equation 26-25evaluates to true.
FR_MCRSFFE = 0
Eqn. 26-24
FID & FR_SFIDAFMRFMSK = FR_SFIDAFVRFVAL & FR_SFIDAFMRFMSK
NOTE
Sync frames are transmitted in the static segment only. Thus FID <= 1023.
Eqn. 26-25
26.6.15.2 Sync Frame Rejection Filtering
The synchronization frame rejection filter is a comparator. The compare value is defined by the Sync
Frame ID Rejection Filter Register (FR_SFIDRFR). A received synchronization frame with the frame ID
FID passes the sync frame rejection filter if Equation 26-26 or Equation 26-27 evaluates to true.
FR_MCRSFFE = 0
Eqn. 26-26
FID  FR_SFIDRFRSYNFRID
NOTE
Sync frames are transmitted in the static segment only. Thus FID <= 1023.
Eqn. 26-27
26-156
PXS20 Microcontroller Reference Manual, Rev. 1
Freescale Semiconductor