LAUNCHXL-F28027F: How to set a part of flash to be persistent

Hi Asha,

You can define it in linker command file. We had many application notes to show how to set a sector FLASH as persistent to store data or emulate EEPROM, you can refer to application notes (SPRAB69) and the chapter 4 of SPRU514I about Linker Command File.

Hi,
Our objective is to save some bytes (32 to 64) so that it can be retrieved on power up. These are some tunable parameters.
So that instead of manually copying from the debugger and saving it to the user.h file, it can be saved and retrieved from some place in flash.

I have also look at the application note APRB69 and SPRU5141

I have looked at the 2 links on the forum:
1. e2e.ti.com/.../55179
2. processors.wiki.ti.com/.../FAQs
section 4.4
Downloaded "EEPROM Emulation With the TMS320F28xxx (sprab69) and the associated code (zip) and looked at the code but confused at the
Choice : F2801x, F2801, F2802, etc but none for F28027F

I tried to follow the code in C:\ti\controlSUITE\libs\utilities\flash_api\2802x\v201a\example_ccsv5\ Example_Flash2802x_API.c

My question is which sector to select:

#if (FLASH_F28027 || FLASH_F28025 || FLASH_F28023)
SECTOR Sector[4] = {
(Uint16 *)0x3F6000,(Uint16 *)0x3F7FFF,
(Uint16 *)0x3F4000,(Uint16 *)0x3F5FFF,
(Uint16 *)0x3F2000,(Uint16 *)0x3F3FFF,
(Uint16 *)0x3F0000,(Uint16 *)0x3F1FFF,
};

So question looking at the map file below I have couple of questions:
1. If I only have 64K of Flash, how does proj_panther.out run from flash? Not sure I follow this because its size if 70KB.
2. It seems that I can only use FLASHB_D or D_FLASHA to emulate eeprom but part of both are being used as shown below in the map file. Is this true?
3. Is there another option?

Any help/suggestion would be very much appreciated.
Thanks,
Asha
=========================================================

I am looking at my build map file, proj_panther.map and the size of proj_panther.out and proj_panther.obj

proj_panther.out = 70KB while proj_panther.out is 415KB
=========================================================
the proj_panther.map shows

OUTPUT FILE NAME: <proj_panther.out>
ENTRY POINT SYMBOL: "code_start" address: 003f7ff6


MEMORY CONFIGURATION

name origin length used unused attr fill
---------------------- -------- --------- -------- -------- ---- --------
PAGE 0:
P_RAML0 00008000 00000980 00000668 00000318 RWIX
OTP 003d7800 00000400 00000000 00000400 RWIX
FLASHB_D 003f0000 00006000 00003f26 000020da RWIX
D_FLASHA 003f6000 00001f80 00000086 00001efa RWIX
CSM_RSVD 003f7f80 00000076 00000000 00000076 RWIX
BEGIN 003f7ff6 00000002 00000002 00000000 RWIX
CSM_PWL_P0 003f7ff8 00000008 00000000 00000008 RWIX
IQTABLES 003fe000 00000b50 00000000 00000b50 RWIX
IQTABLES2 003feb50 0000008c 00000000 0000008c RWIX
IQTABLES3 003febdc 000000aa 00000000 000000aa RWIX
ROM 003ff27c 00000d44 00000000 00000d44 RWIX
RESET 003fffc0 00000002 00000000 00000002 RWIX
VECTORS 003fffc2 0000003e 00000000 0000003e RWIX

PAGE 1:
RAMM0_M1 00000000 00000600 0000055f 000000a1 RWIX
D_RAML0 00008980 00000680 00000000 00000680 RWIX

Hi,
I could not find spru5141
Thanks,
Asha

This is the document in question: www.ti.com/.../spru514l.pdf

Sean

Hi Sean,
I had eventually found and scanned thru chapter 4.
I just want to confirm the following that on reboot, the array test_persistent[] holds values from run time on power up:
If in my F28027F.cmd file, I add "myPersistent :> D_RAML0 Page=1"
and then in my *.c file, I add
"unit16_t test_persistent[4];
#pragma DATA_SECTION(test_persistent, "myPersistent");"

and then test_persistent[] array is updated on run time. On power up, the test_persistent[] array has retained the value from the run time?

Thank you very much,
Asha

Asha,

You have to reserve 1 flash sector to store tunable parameters and find a way to store all other code /data in remaining flash sectors.

Regards,
Manoj

Since this is old thread. If I don't see any activity for next 3 days. I shall be closing this thread.