4 MCC Melody Components

Libraries can be selected from Device Resources to be made available in Project Resources.

The Easy View for Libraries relates to software configuration settings, i.e., will not have anything to do with registers for hardware peripheral or off-chip components. For example, the Data Streamer Library implements the Data Stream Protocol needed to plot multiple variables on the MPLAB Data Visualizer. Its configuration is a list of variables and their respective types.

Libraries provide a portable interface that can be ported to multiple MCU devices.

Drivers can be selected from Available or Device Resources and be made available in Project Resources.

The Drivers provide an abstracted configuration interface. In the Timer Driver example below, one chooses the Timer hardware instance to run the Timeout functionality.

Drivers and Libraries may provide a portable interface consistent across different MCU devices. So, one is able to have a very similar interface to very different hardware peripherals. The interface will be provided in the form of a driver_interface.h file, containing a DRIVER_INTERFACE struct, which in this example defines the portable interface associated with the timer. In the image below, TMR_INTERFACE defines the portable interface associated with the timer.

When writing code, one can reference the DRIVER_INTERFACE similarly to the way this is defined in the header file, as shown in the image below.

First, initialize the pointer to point to the address of the structure itself, then the interface API can be accessed as structure members. See pointers to structures.

ptrName = &structVariable;
ptrName —> memberName

An example application-level code for the dsPIC33CK is listed below, showing the use of the TimeoutCallbackRegister API from the Timer Interface.

#include "mcc_generated_files/system/system.h"

void Timer_Callback_100ms(void){
    LED_Toggle();
}

/*
    Main application
*/
int main(void)
{
    SYSTEM_Initialize();
    Timer->TimeoutCallbackRegister(Timer_Callback_100ms);   
    while(1){}    
}

For most Peripheral Drivers, the PLIBS are automatically selected and added to the Project. The PLIBs provide a non-portable interface and are only accessible from the Builder view when the corresponding driver is added to the Project Resources. They are hidden from the Device Resources, Project Resources.

Some of the PLIBs might be available to be selected from the Device Resources.

The PLIBs can provide an Easy View to allow you to configure device-specific settings, which is optional, and PLIBS can choose not to provide that.

The PLIBs provide a fully functional interface for the peripheral functionality, but which is not fully provided by the Driver. In the image below, one can see the MPLAB X IDE Navigator view of the generated API.

The initializer can be selected from Available or Device Resources and be made available in Project Resources.

The Initializers allow for Register Initialization, using the bit and register fields, as shown below.

A single function which initializes the peripheral <PERPHERAL>_Initialize( ) i.e., TMR0_Initialize( ); is generated.

The Initialize function has code comments to describe the settings made.

The TMR1_Initialize function corresponding to the above configuration is shown below. Note how the configured settings are described in the generated comments.

An MCC Melody project, from the start of main( ), will call SYSTEM_Initialize();

This function, in turn, will call functions that initialize various system drivers and any other drivers which are added to the project.

void SYSTEM_Initialize(void)
{
    CLOCK_Initialize();
    PIN_MANAGER_Initialize();
    INTERRUPT_Initialize();
    Peripheral1_Initialize();
    Peripheral1_Initialize();
}

Three configuration screens handle pin configuration: Pins View, Pins Package view, and Pins Grid View.

The interrupt manager functions as an indexing page, like a list of all peripheral interrupts.

The ISR is typically used to clear interrupt flags, then set the associated callback function, ensuring to keep the ISR sufficiently short to reduce the likelihood of interrupts interrupting each other and the appurtenant complexity of handling this safely.

A default overflow callback is provided (see the example below from tmr0.h). If you would like to place the callback at a specific place in your application (e.g., in main.c), it is then recommended to use the DriverXCallbackRegister() function, e.g., Timer.TimeoutCallbackRegister(Callback_name);