RTOS/AMIC110: Aligning tasks to EtherCAT SYNC0 signal

Hi Nathan

It is possible to use GP Timer for this purpose. This will require a handoff and/or synchronization from the GP timer to the IEP timer as slave transitions to SafeOP.  Unfortunately - we don’t have recommended implementation for this.

The GP timer is a free-running upward counter that can be read and written to while running.

It has two possible clock sources

• 32-kHz clock

• System clock

• The selection is done in the PRCM configuration

The timer has a Autoreload capability on overflow and compare logic to generate an interrupt event.

We can program the timer duration by

• When the timer Overflows at: 0xFFFFFFFF

• We set the Autoreload: 0xFFFFFFFF – (cycleTime/50) + 1 to be the desired duration.

• The rate can be adjusted by increasing and decreasing the offset from Autoreload value

When the IEP starts running, a clock switch will need to be implemented that graceful transition from the GP Timer to the IEP timer with the desired transition characteristics.