21.4. Driver Implementation
System Clock Driver
When configured as the system clock, the interval timer core runs continuously in periodic mode, using the default period set. The system clock services are then run as a part of the interrupt service routine for this timer. The driver is interrupt-driven and therefore must have its interrupt signal connected in the system hardware.
Platform Designer allows you to specify system library properties that determine which timer device will be used as the system clock timer.
Timestamp Driver
- The timer has a writeable period register, as configured in Platform Designer.
- The timer is not selected as the system clock.
Platform Designer allows you to specify system library properties that determine which timer device will be used as the timestamp timer. If the timer hardware is not configured with writeable period registers, calls to the alt_timestamp_start() API function will not reset the timestamp counter. All other HAL API calls will perform as expected.
Limitations
The HAL driver for the interval timer core does not support the watchdog reset feature of the core.