FlexRay Communication Controller (FlexRay)MPC5644A Microcontroller Reference Manual, Rev. 6Freescale Semiconductor 1593After reading all the data from the locked tables, the application must unlock the table by writing to theeven table lock trigger FR_SFTCCSR[ELKT] again. The even table lock status bit FR_SFTCCSR[ELKS]is reset immediately.If the sync frame table generation is disabled, the table valid bits FR_SFTCCSR[EVAL] andFR_SFTCCSR[EVAL] are reset when the counter values in the Sync Frame Counter Register(FR_SFCNTR) are updated. This is done because the tables stored in the FlexRay memory area are nolonger related to the values in the Sync Frame Counter Register (FR_SFCNTR).Figure 33-155. Sync frame table trigger and generation timing33.6.12.5 Sync frame table accessThe sync frame tables will be transferred into the FlexRay memory area during the table write windowsshown in Figure 33-155. During the table write, the application can not lock the table that is currentlywritten. If the application locks the table outside of the table write window, the lock is grantedimmediately.33.6.12.5.1 Sync frame table locking and unlockingThe application locks the even/odd sync frame table by writing 1 to the lock trigger bit ELKT/OLKT inthe Sync Frame Table Configuration, Control, Status Register (FR_SFTCCSR). If the affected table is notcurrently written to the FlexRay memory area, the lock is granted immediately, and the lock status bitELKS/OLKS is set. If the affected table is currently written to the FlexRay memory area, the lock is notgranted. In this case, the application must issue the lock request again until the lock is granted.The application unlocks the even/odd sync frame table by writing 1 to the lock trigger bit ELKT/OLKT.The lock status bit ELKS/OLKS is cleared immediately.33.6.13 MTS generationThe CC provides a flexible means to request the transmission of the Media Access Test Symbol MTS inthe symbol window on channel A or channel B.The application can configure the set of communication cycles in which the MTS will be transmitted overthe FlexRay bus by programming the CYCCNTMSK and CYCCNTVAL fields in the MTS AConfiguration Register (FR_MTSACFR) and MTS B Configuration Register (MTSBCFR).The application enables or disables the generation of the MTS on either channel by setting or clearing theMTE control bit in the MTS A Configuration Register (FR_MTSACFR) or MTS B Configuration Register(MTSBCFR). If an MTS is to be transmitted in a certain communication cycle, the application must setthe MTE control bit during the static segment of the preceding communication cycle.FR_SFTCCSR.[OPT,SIDEN,SDVEN] write windoweven table writestatic segment NIT static segment NIT static segment NITcycle 2n-1 cycle 2n cycle 2n+1odd table write
