SPC58 data sharing between two cores

[masterduff09]

I've been using for a bit a SPC58 eval-board and i was wondering how to share global variables between the two cores. I searched around on the internet finding nothing useful. Is "volatile int" enough even for a rough and dirty data sharing or should I use something like SRAM and its shared memory location?

[Erwan YVIN · Accepted solution]

Hello Mark ,

take a look in SPC58xNxx_RLA TripleCore Test Application for start

yes , volatile is not enough.

you should create a sort of shared SRAM in application.ld and define :

// Define shared variables in shared SRAM
volatile int sharedvar __attribute__((section(".shared_sram")));

After checking , you should define a sort of SpinLock before accessing or writing it. 

          Best regards

                      Erwan

[masterduff09]

Hi Erwan,

thank you for answer.

How should I choose parameters for that section? I don't want to mess with already used memory partitions.

SPC58xNxx_RLA TripleCore Test Application does not implement data sharing between cores but only starting the additional cores and make the onboard LED blink. Are there any other sources from where I can get more info about this topic?

Thanks in advance, Mark

[Erwan YVIN]

Hello Mark ,

Sorry , we have no example.

You have no choice you should update your linker script copy application.ld  by user.ld

and try to create a shared ram data in user.ld

MEMORY
{   
    ...........
    shared_sram : org = tbd, len = 16k  /* Define shared SRAM region */
    ...........
}

SECTION
{
    .......
    .shared_sram : 
    {
        . = ALIGN(4);
        *(.shared_sram)
        . = ALIGN(4);
    } > shared_sram
    ....
}

   Best regards

              Erwan