3.2.12 DIAG_FREQM

The DIAG_FREQM module is designed to verify the correct functionality of the Frequency Measurement (FREQM) through a set of C function calls.

Note: This module contains routines which sets the main clock at 48 MHz. The user would need to call DIAG_OSCCTRL_Initialize to restore the clock.

The DIAG_FREQM software test API is mapped to the following safety mechanisms:

Table 3-13.
Function	Diagnostic Mechanism	Use Case	Elasped Timer (μs) ~
DIAG_FREQM_ClockCalibration()	FREQM_CLOCK_CALIBRATION	POST / OnDemand	54.14
DIAG_FREQM_SFRReset()	SFR_RESET_STATE	POST	16.04
DIAG_FREQM_SFRWriteRead()	SFR_WRITE_READ	POST / OnDemand	37.22

Configuring the Diagnostic

FREQM Safe-Plib can be configured as illustrated to supported to support all diagnostics:

Run-time Pre-requisites

DIAG_FREQM_SFRRead should be executed before DIAG_FREQM_SFRWriteRead

DIAG_GCLK_Initialize should be executed to initialize the clock

DIAG_FREQM_MeasurementStart should be executed to start the measurement

Using the Diagnostic

#include "definitions.h"

DIAG_TEST_STATUS DIAG_FREQM_SFRPost()
{
    DIAG_TEST_STATUS result[NO_OF_FREQM_SFRPOST_TESTS]; 
    DIAG_TEST_STATUS test_status = DIAG_TEST_FAILED;
    int i;
    
    result[0] = DIAG_FREQM_SFRReset(NULL,0,false);
    result[1] = DIAG_FREQM_SFRWriteRead(NULL,0,false);
    // DO ADDITIONAL POST TESTS HERE
    
    for(i=0; i < NO_OF_FREQM_SFRPOST_TESTS; i++)
    {
        if (result[i] != DIAG_TEST_PASSED)
        {
            test_status = result[i];
            break;
        }
        else
        {
            test_status = DIAG_TEST_PASSED;
        }
    }
    return test_status;
}

DIAG_TEST_STATUS DIAG_FREQM_Post()
{
    return DIAG_FREQM_Calibration(DIAG_GCLK1, DIAG_GCLK2);
}

void DIAG_FREQM_Post_Pre()
{
    // Initialize the dependent peripherals required to run the GCLK test.
    DIAG_GCLK_Initialize(DIAG_GCLK1, (uint16_t)(48000000/6000000));

    // Start the frequency measurement.
    DIAG_FREQM_MeasurementStart();    
}