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Excessive Memory Usage with PIC32 port

Posted by Grant Brown on October 23, 2008
Hi,

Port : PIC32

I have stripped all of the custom tasks etc out of the PIC32 demo and removed the source files etc for the above tasks.

This has resulted in a program with only 3 custom tasks (I wrote them and 1 is copied below for reference) which simply flash LED's. All there tasks are contained in the main file (main.c)

But when I compile the program and then check the memory usage I end up with the following memory usage as reported by the MPLabs Memory Usage Gauge,

Program Memory : 18600 Bytes (out of 536560)
Data Memory : 31404 Bytes (out of 32768)

This really seems excessive given that whats left is basically an empty project with the RTOS just ticking over.

Am I missing something or is it normal for 95% of the data memory to be used up like this.

The project files are,

Source files,

..\..\Source\list.c
..\..\Source\portable\MemMang\heap_2.c
..\..\Source\portable\MPLAB\PIC32MX\port.c
..\..\Source\portable\MPLAB\PIC32MX\port_asm.c
..\..\Source\queue.c
..\..\Source\tasks.c

Header Files

..\..\Source\include\croutine.h
..\..\Source\include\FreeRTOS.h
..\..\Source\include\list.h
..\..\Source\include\portable.h
..\..\Source\include\projdefs.h
..\..\Source\include\queue.h
..\..\Source\include\semphr.h
..\..\Source\include\task.h
..\..\Source\portable\MPLAB\PIC32MX\portmacro.h
C:\Program Files\Microchip\FreeRTOS\Demo\PIC32MX_MPLAB\FreeRTOSConfig.h

Here is a typical custom task

static void Grants_Task( void *pvParameters )
{
portTickType xLastExecutionTime;
xLastExecutionTime = xTaskGetTickCount();
for( ;; )
{
vTaskDelayUntil( &xLastExecutionTime, 1000 );
PORTToggleBits(IOPORT_D, BIT_0);
}
}

Kind Regards
Grant Brown






RE: Excessive Memory Usage with PIC32 port

Posted by Dave on October 23, 2008
This really should be an FAQ. All you are seeing is the heap RAM which will mostly be free RAM and can be set using the configTOTAL_HEAP_SIZE setting in FreeRTOSConfig.h. http://www.freertos.org/a00111.html


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