Nios® V Processor Software Developer Handbook

ID 743810
Date 9/26/2022
Public

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6.7. Using Timer Devices

Timer devices are hardware peripherals that count clock ticks and can generate periodic interrupt requests. You can use a timer device to provide a number of time-related facilities, such as the HAL system clock, alarms, the time-of-day, and time measurement. To use the HAL timer facilities, the Nios® V processor system can either leverage the internal Nios® V processor timer or include a timer peripheral.

The HAL API provides two types of timer device drivers:

  • System clock driver—Supports alarms, such as you would use in a scheduler.
  • Timestamp driver—Supports high-resolution time measurement.

A timer peripheral can behave as either a system clock or a timestamp, but not both.

For more information about where the HAL-specific API functions for accessing timer devices are defined, refer to the sys/alt_alarm.h and sys/alt_timestamp.h files.