21.5.3 Continuous Period Mode

When the PIT64B_MR.CONT bit is written to 1, the PIT64B continuously produces timer events. The timer is started as soon as the PIT64B_CR.START bit is written to 1. The period is defined by configuring the PIT64B_LSBPR.LSBPERIOD field and PIT64B_MSBPR.MSBPERIOD field. When the START command is issued, the 64-bit timer loads 0 and increments up to LSBPERIOD and MSBPERIOD field value minus 1, then automatically reloads 0 anc restarts a new counting period until bit PIT64B_CR.SWRST is written to 1.

When the timer reaches its maximum value, the flag PIT64B_ISR.PERIOD is set. PIT64B_ISR.PERIOD is cleared when reading PIT64B_ISR. If a new period elapses and the PIT64B_ISR.PERIOD is 1, the PIT64B_ISR.OVRE flag is set to indicate a potential latency at system level

After the START command has been issued, any new values written in PIT64B_MR, PIT64B_LSBPR or PIT64B_MSBPR have no effect on the current period if bit PIT64B_MR.SMOD=0 (see Figure 21-4). A software reset must be issued before configuring new values in PIT64B_LSBPR and PIT64B_MSBPR if bit PIT64B_MR.SMOD=0.

If PIT64B_MR.SMOD=1 a start can be also performed as soon as PIT64B_LSBPR is written, thus a modification of the period can be performed on-the-fly with a single write operation if the period requires no more than 32 bits. When writing a 64-bit value, the 32-bit MSB part must be configured first followed by a 32-bit LSB part (see Figure 21-5). When configuring a value lower or equal to 32 bits after processing a period defined on 64 bits, first PIT64B_MSBPR must be written to 0, and then the 32-bit LSB must be written into PIT64B_LSBPR.

If PIT64B_CR.SWRST is written to 1, the current period is immediately stopped.