4.2 MCC Melody Implementation

Create a new MPLAB X IDE project for AVR16EB32.

Open MCC from the toolbar (more information on installing the MCC plug-in can be found here).

In MCC Content Manager Wizard select, MCC Melody, then click Finish.

Click on Project Resources, go to System, select Interrupt Manager and toggle the Global Interrupt Enable button.

Go to Project Resources, click System, then click CLKCTRL and disable the Prescaler enable button.

From the Device Resources, go to Drivers and click the Timer window, add the TCE module, then do the following configuration:

– Enable Timer: May be enabled by default. If not, just toggle the button (it turns blue if enabled)

– Clock Divider: System clock (by default, the divider should be 1 - System clock)

– Waveform Generation Mode: Single-slope PWM mode

– Requested Period[s]: 0.00005

– Waveform Output n: Check the boxes from the Enable column for Waveform Output 0, 1, 2, 3

– Generate ISR: Toggle the button (it turns blue if enabled)

– Enable Compare 0 Interrupt: Toggle the button (it turns blue if enabled)

– Enable Compare 1 Interrupt: Toggle the button (it turns blue if enabled)

– Enable Compare 2 Interrupt: Toggle the button (it turns blue if enabled)

– Enable Compare 3 Interrupt: Toggle the button (it turns blue if enabled)

From the Device Resources, click the Drivers window, add the WEX module, then do the following configuration:

– Input Matrix: Direct

– Update Source: TCE (the update condition for the output signals will be dictated by TCE)

– Override Settings: Check all the boxes from the Output Enable column for the Waveform Output [0-7]

– Dead-time Insertion Channel 0 Enable: Toggle the button (it turns blue if enabled)

– Dead-time Insertion Channel 1 Enable: Toggle the button (it turns blue if enabled)

– Dead-time Insertion Channel 2 Enable: Toggle the button (it turns blue if enabled)

– Dead-time Insertion Channel 3 Enable: Toggle the button (it turns blue if enabled)

– Requested Dead-time Low Side (μs): 0.150

– Requested Dead-time High Side (μs): 0.250

– Fault Event Input A: Toggle the button (it turns blue if enabled)

– Fault Enable: Toggle the button (it turns blue if enabled)

– Fault Interrupt Enable: Toggle the button (it turns blue if enabled)

– Fault Detection Restart Mode: Cycle-by-cycle

– Fault Detection Action: Low

From the Device Resources, go to the Drivers window, add the EVSYS module, then follow the below configuration:

– CHANNELS: CHANNEL0

– USERS: WEXA (Select CHANNEL0 rectangle from CHANNELS tab, hold and drag the cursor to the WEXA rectangle from the USERS tab)

In the Pin Grid View window check if the WEX_WO[0-7] pins are locked as outputs on PORTA. When the boxes from Enable column from Waveform Output n are checked, the pins are also locked. To change the PORT click on a pin from another PORT in Pin Grid View.

In the Project Resources window, click the Generate button so that MCC will generate all the specified drivers and configurations.

Edit the main.c file, as following:

Add in the include files the following:


#include "mcc_generated_files/system/system.h"
#include <util/delay.h>

Add macro definitions:


#define TCE_PERIOD                              (0x3E8)
#define MAX_DUTY_CYCLE                          (0x3DE)

Add ISR callback functions:


/* Callback function that is called in the ISR routine */
void UserCallback_CMP0(void)
{
    static uint16_t duty_cycle = 0;

    /* Duty cycle update in interrupt */
    duty_cycle += 5;
    if(duty_cycle >= MAX_DUTY_CYCLE)
      duty_cycle = 0;
    TCE0_PWM_BufferedDutyCycle0Set(duty_cycle);
}

/* Callback function that is called in the ISR routine */
void UserCallback_CMP1(void)
{
    static uint16_t duty_cycle = 0;

    /* Duty cycle update in interrupt */
    duty_cycle += 15;
    if(duty_cycle >= MAX_DUTY_CYCLE)
      duty_cycle = 0;
    TCE0_PWM_BufferedDutyCycle1Set(duty_cycle);
}

/* Callback function that is called in the ISR routine */
void UserCallback_CMP2(void)
{
    static uint16_t duty_cycle = 0;

    /* Duty cycle update in interrupt */
    duty_cycle += 25;
    if(duty_cycle >= MAX_DUTY_CYCLE)
      duty_cycle = 0;
    TCE0_PWM_BufferedDutyCycle2Set(duty_cycle);
}

/* Callback function that is called in the ISR routine */
void UserCallback_CMP3(void)
{
    static uint16_t duty_cycle = 0;

    /* Duty cycle update in interrupt */
    duty_cycle += 35;
    if(duty_cycle >= MAX_DUTY_CYCLE)
      duty_cycle = 0;
    TCE0_PWM_BufferedDutyCycle3Set(duty_cycle);
}

Add functions:

void Create_Fault(void)
{
    /* Fault creation, repeat in main loop to see it on Logic Analyzer. This is an event
     * generated using a software command */
    EVSYS_SoftwareEventASet(EVSYS_SWEVENTA_CH0_gc);
}

void Clear_Fault(void)
{
    /* Clear fault condition using a software command */
    WEX0_SoftwareCommand(WEX_CMD_FAULTCLR_gc);
}

Edit the main function:

int main(void)
{
    SYSTEM_Initialize();

    TCE0_Compare0CallbackRegister(UserCallback_CMP0);
    TCE0_Compare1CallbackRegister(UserCallback_CMP1);
    TCE0_Compare2CallbackRegister(UserCallback_CMP2);
    TCE0_Compare3CallbackRegister(UserCallback_CMP3);

    while(1)
    {
      Create_Fault();
      _delay_us(250);
      Clear_Fault();
      _delay_us(250);
    }    
}

Now, the project can be built and run using MPLAB X IDE. During the run time, the scaling value for the compare registers modifies every 10 ms, and the range of the duty cycles will be accordingly.