TMS320F28020: Writing app data to Flash like an EEPROM

Robin,

From a Flash technology the F28020 device is the same as the F28069 so I see no technical reason this should not work on this device.  Let's see what we run into, but I suspect the small amount of RAM may be why this device is not listed in that app note.  I may need to do a bit more research to see what memory shuffling we might need to do.

Let me know what you see when trying to add/fit this in your device.

Best,

Matthew

Hi Matthew,

I followed the "Flash2802x_API_Quickstart.pdf" guide I found here: C:\ti\C2000Ware_4_01_00_00\libraries\flash_api\f2802x\docs.

I'm calling Flash_Program() in the main() idle loop as follows:

        case SOS:   //h Easter egg, not documented, SOS blink on LED
        {
            Uint16  Status;
            Uint32 Length = 4;
            FLASH_ST ProgStatus;

            GPIO_toggle(myGpio, RED_LED);///
            Write_Buffer_calVals[0] = 0xdead;
            Write_Buffer_calVals[1] = 0xbeef;

            EALLOW;
            Flash_CPUScaleFactor = SCALE_FACTOR;
            Flash_CallbackPtr = NULL;
            EDIS;

            calVals_Pointer = (Uint32 *)0x3F6000;   // Sector C

            EALLOW;
            DINT;
            EDIS;

            Status = Flash_Program((Uint16 *)calVals_Pointer,(Uint16 *)Write_Buffer_calVals,Length,&ProgStatus);

            EALLOW;
            EINT;
            EDIS;

            calVals_Pointer = (Uint32 *)0x3F6000;   // Sector C
            Read_Buffer_calVals[0] = *(calVals_Pointer++);
            Read_Buffer_calVals[1] = *(calVals_Pointer);

            out[0]  = (unsigned int)Read_Buffer_calVals[0] >> 0;
            out[1]  = (unsigned int)Read_Buffer_calVals[1] >> 0;
            out[2]  = (unsigned int)Read_Buffer_calVals[0] >> 0;
            out[3]  = (unsigned int)Read_Buffer_calVals[1];
            out[4]  = 0x0a;        // Line feed
            out[5]  = 0x0d;        // Carriage return
            out[6]  = 0x00;        // Null

            sciMasterTransmit((const char *)out);
        }
        break;

Watching the disassembly window while stepping through code, As seen here, it appears to be running from flash, not RAM:

Question #1:

Since this function (or macro) is part of the flash API library, how do I memcpy() it to RAM?

When I let the code run, it produces the following source file error:

I wasn't able to locate the file, "Flash28_Prog.c".

Question #2:

Where can I find this file?

Thanks,
robin

New info:

I added "2802x_FlashAPI_BootROMSymbols_v2.01.lib" to the project and now flash API functions run from ROM.

Thanks for your help Matthew.

So, if anyone ever asks again, yes you can use the on-board flash of the TMS320F2820 for nonvolatile storage of application variables.

Thanks again!

Correction: the part in question is:  TMS320F28020

Thanks for the follow up Robin, glad this was able to work for your application.

Best,

Matthew