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Chapter 13 FlexRay Communication Controller (FLEXRAY)
MC9S12XF - Family Reference Manual, Rev.1.19
594
Freescale Semiconductor
13.6.12.3 Sync Frame ID and Sync Frame Deviation Table Setup
The FlexRay block writes a copy of the internal synchronization frame ID and deviation tables into the
FRM if requested by the application. The application must provide the appropriate amount of FRM for the
tables. The memory layout of the tables is given in
Figure 13-138. Each table occupies 120 16-bit entries.
While the protocol is in POC:cong state, the application must program the offsets for the tables into the
13.6.12.4 Sync Frame ID and Sync Frame Deviation Table Generation
The application controls the generation process of the Sync Frame ID and Sync Frame Deviation Tables
The Sync Frame Table generation process is described in the following for the even cycle. The same
sequence applies to the odd cycle.
If the application has enabled the sync frame table generation by setting SFTCCSR.SIDEN to 1, the
FlexRay block starts the update of the even cycle related tables after the start of the NIT of the next even
cycle. The FlexRay block checks if the application has locked the tables by reading the SFTCCSR.ELKS
lock status bit. If this bit is set, the FlexRay block will not update the table in this cycle. If this bit is cleared,
the FlexRay block locks this table and starts the table update. To indicate that these tables are currently
updated and may contain inconsistent data, the FlexRay block clears the even table valid status bit
SFTCCSR.EVAL. Once all table entries related to the even cycle have been transferred into the FRM, the
FlexRay block sets the even table valid bit SFTCCSR.EVAL and the Even Cycle Table Written Interrupt
an interrupt request is generated.
To read the generated tables, the application must lock the tables to prevent the FlexRay block from
updating these tables. The locking is initiated by writing a 1 to the even table lock trigger
SFTCCSR.ELKT. When the even table is not currently updated by the FlexRay block, the lock is granted
and the even table lock status bit SFTCCSR.ELKS is set. This indicates that the application has
successfully locked the even sync tables and the corresponding status information elds SFRA, SFRB in
Table 13-112. Sync Frame Table Generation Modes
SFTCCSR
Description
OPT
SDVEN
SIDEN
0
No Sync Frame Table copy
0
1
Sync Frame ID Tables will be copied continuously
0
1
0
Reserved
0
1
Sync Frame ID Tables and Sync Frame Deviation Tables will be copied continuously
1
0
No Sync Frame Table copy
1
0
1
Sync Frame ID Tables for next even-odd-cycle pair will be copied
0
1
0
Reserved
1
Sync Frame ID Tables and Sync Frame Deviation Tables for next even-odd-cycle pair will be
copied