Introduction

This is the documentation for the data structures, functions, variables, defines, enums, and typedefs for the FREQM driver.

The Frequency Meter(FREQM) can be used to accurately measure the frequency of a clock by comparing it to a known reference clock.

Main Files

This example shows the user how to use frequency meter

OSC32K set as reference clock(32768Hz)
CPU,HSB,PBA,PBB set as measured clock
Results output through usart:
- UC3C_EK: main clock 16Mhz
  - CPU, HSB, PBA equals main clock 16MHz
  - PBB equals main clock 16Mhz
  - PBB equals main clock divided by 16 after set PBB clock division
- UC3L_EK: main clock 96Mhz
  - CPU, HSB, PBA equals main clock divided by 8, 12Mhz
  - PBB equals main clock divided by 8, 12Mhz
  - PBB equals main clock divided by 16 after set PBB clock division
- STK600-RCUC3D: main clock 12Mhz
  - CPU, HSB, PBA equals main clock 12MHz
  - PBB equals main clock 12Mhz
  - PBB equals main clock divided by 16 after set PBB clock division
Two mode support
- Normal Mode: default mode
- Interrupt Mode: open INTERRUPT_MODE_SUPPORT

This software was written for the GNU GCC for AVR32 and IAR Systems compiler for AVR UC3. Other compilers may or may not work.

This example has been tested with the following configuration:

UC3C_EK and UC3L_EK evaluation kit or STK600-RCUC3D;
CPU clock: 16 MHz(UC3C_EK), 12MHz(UC3L_EK, STK600-RCUC3D);
USART2 (UC3C_EK),USART3(UC3L_EK) or RS232 (STK600-RCUC3D) abstracted with a USB CDC connection to a PC;
PC terminal settings:
- 57600 bps,
- 8 data bits,
- no parity bit,
- 1 stop bit,
- no flow control.

For further information, visit Atmel AVR UC3.
Support and FAQ: https://www.microchip.com/support/