Clock Frequency Calculator

Calculate clock period, instruction throughput, and timer settings from an oscillator or PLL frequency.

MHz

CPI: 1 for ARM Cortex-M, 4 for classic AVR

Clock Period

62.50 ns

Instructions per Second16.0 MIPS
Timer Tick Frequency250,000.0 Hz
Timer Tick Period4.000 µs

Clock Period vs Clock Frequency

Clock Frequency and Timer Calculations

The clock frequency determines the speed of all operations in a microcontroller.

Formulas

Clock Period = 1 / Frequency

MIPS = Clock Frequency / Cycles per Instruction

Timer Frequency = Clock / Prescaler

Prescalers divide the clock to create slower timer ticks, useful for generating precise time intervals without consuming CPU cycles.

Example Calculation

16 MHz clock, 1 CPI (ARM Cortex-M), prescaler of 64.

  1. 01Clock period: 1 / 16e6 = 62.5 ns
  2. 02MIPS: 16e6 / 1 = 16 MIPS
  3. 03Timer frequency: 16e6 / 64 = 250,000 Hz
  4. 04Timer tick: 64 / 16e6 = 4.000 microseconds

Frequently Asked Questions

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