TMS570LC4357: Prefetch exception during erase flash using fapi

Milin P.

I'm trying to erase a sector in flash but when I call Fapi_issueAsyncCommandWithAddress(), my code will not proceed further and I will get a prefetch exception. I noticed that I can get past that function and execute some number of lines after that but eventually, a prefetch exception occurs. Here's the code for erasing:

typedef struct Sectors
{
    uint32_t            start;
    uint32_t            length;
    Fapi_FlashBankType  bankNumber;
    uint8_t             sectorNumber;
} SECTORS;
#define HCLK_FREQ    150U
#define WAIT_FSM_READY()        { while (FLASH_CONTROL_REGISTER->FmStat.FMSTAT_BITS.BUSY == (uint32_t)Fapi_Status_FsmBusy) {} }

#define BL_INFO_SECTOR_ID    0x3u

void dummyFunc(void) 
{
    Fapi_initializeFlashBanks(HCLK_FREQ);
    Fapi_setActiveFlashBank(flash_sector[BL_INFO_SECTOR_ID].bankNumber);
    WAIT_FSM_READY();
    Fapi_enableMainBankSectors((uint16_t)(0x0001U << BL_INFO_SECTOR_ID));
    WAIT_FSM_READY();
    Fapi_issueAsyncCommandWithAddress(Fapi_EraseSector, (uint32_t*)flash_sector[BL_INFO_SECTOR_ID].start);
    WAIT_FSM_READY();

}

const SECTORS flash_sector[NUMBEROFSECTORS]=
{
    0x00000000U, 0x04000U, Fapi_FlashBank0,  0U,
    0x00004000U, 0x04000U, Fapi_FlashBank0,  1U,
    0x00008000U, 0x04000U, Fapi_FlashBank0,  2U,
    0x0000C000U, 0x04000U, Fapi_FlashBank0,  3U,
    0x00010000U, 0x04000U, Fapi_FlashBank0,  4U,
    0x00014000U, 0x04000U, Fapi_FlashBank0,  5U,
    0x00018000U, 0x08000U, Fapi_FlashBank0,  6U,
    0x00020000U, 0x20000U, Fapi_FlashBank0,  7U,
    0x00040000U, 0x20000U, Fapi_FlashBank0,  8U,
    0x00060000U, 0x20000U, Fapi_FlashBank0,  9U,
    0x00080000U, 0x40000U, Fapi_FlashBank0, 10U,
    0x000C0000U, 0x40000U, Fapi_FlashBank0, 11U,
    0x00100000U, 0x40000U, Fapi_FlashBank0, 12U,
    0x00140000U, 0x40000U, Fapi_FlashBank0, 13U,
    0x00180000U, 0x40000U, Fapi_FlashBank0, 14U,
    0x001C0000U, 0x40000U, Fapi_FlashBank0, 15U,

    0x00200000U, 0x20000U, Fapi_FlashBank1,  0U,
    0x00220000U, 0x20000U, Fapi_FlashBank1,  1U,
    0x00240000U, 0x20000U, Fapi_FlashBank1,  2U,
    0x00260000U, 0x20000U, Fapi_FlashBank1,  3U,
    0x00280000U, 0x20000U, Fapi_FlashBank1,  4U,
    0x002A0000U, 0x20000U, Fapi_FlashBank1,  5U,
    0x002C0000U, 0x20000U, Fapi_FlashBank1,  6U,
    0x002E0000U, 0x20000U, Fapi_FlashBank1,  7U,
    0x00300000U, 0x20000U, Fapi_FlashBank1,  8U,
    0x00320000U, 0x20000U, Fapi_FlashBank1,  9U,
    0x00340000U, 0x20000U, Fapi_FlashBank1, 10U,
    0x00360000U, 0x20000U, Fapi_FlashBank1, 11U,
    0x00380000U, 0x20000U, Fapi_FlashBank1, 12U,
    0x003A0000U, 0x20000U, Fapi_FlashBank1, 13U,
    0x003C0000U, 0x20000U, Fapi_FlashBank1, 14U,
    0x003E0000U, 0x20000U, Fapi_FlashBank1, 15U,

    0xF0200000U, 0x01000U, Fapi_FlashBank7,  0U,
    0xF0200000U, 0x01000U, Fapi_FlashBank7,  1U,
    0xF0200000U, 0x01000U, Fapi_FlashBank7,  2U,
    0xF0200000U, 0x01000U, Fapi_FlashBank7,  3U,
    0xF0200000U, 0x01000U, Fapi_FlashBank7,  4U,
    0xF0200000U, 0x01000U, Fapi_FlashBank7,  5U,
    0xF0200000U, 0x01000U, Fapi_FlashBank7,  6U,
    0xF0200000U, 0x01000U, Fapi_FlashBank7,  7U,
    0xF0200000U, 0x01000U, Fapi_FlashBank7,  8U,
    0xF0200000U, 0x01000U, Fapi_FlashBank7,  9U,
    0xF0200000U, 0x01000U, Fapi_FlashBank7, 10U,
    0xF0200000U, 0x01000U, Fapi_FlashBank7, 11U,
    0xF0200000U, 0x01000U, Fapi_FlashBank7, 12U,
    0xF0200000U, 0x01000U, Fapi_FlashBank7, 13U,
    0xF0200000U, 0x01000U, Fapi_FlashBank7, 14U,
    0xF0200000U, 0x01000U, Fapi_FlashBank7, 15U,
    0xF0200000U, 0x01000U, Fapi_FlashBank7, 16U,
    0xF0200000U, 0x01000U, Fapi_FlashBank7, 17U,
    0xF0200000U, 0x01000U, Fapi_FlashBank7, 18U,
    0xF0200000U, 0x01000U, Fapi_FlashBank7, 19U,
    0xF0200000U, 0x01000U, Fapi_FlashBank7, 20U,
    0xF0200000U, 0x01000U, Fapi_FlashBank7, 21U,
    0xF0200000U, 0x01000U, Fapi_FlashBank7, 22U,
    0xF0200000U, 0x01000U, Fapi_FlashBank7, 23U,
    0xF0200000U, 0x01000U, Fapi_FlashBank7, 24U,
    0xF0200000U, 0x01000U, Fapi_FlashBank7, 25U,
    0xF0200000U, 0x01000U, Fapi_FlashBank7, 26U,
    0xF0200000U, 0x01000U, Fapi_FlashBank7, 27U,
    0xF0200000U, 0x01000U, Fapi_FlashBank7, 28U,
    0xF0200000U, 0x01000U, Fapi_FlashBank7, 29U,
    0xF0200000U, 0x01000U, Fapi_FlashBank7, 30U,
    0xF0200000U, 0x01000U, Fapi_FlashBank7, 31U
};

The instruction fault status register has 0x1000000001008 in it and the instruction fault address register has 0x0000000C in it. I verified that I'm enabling the banks and setting them up properly as well. I am running the fapi functions from RAM by using the following in my linker:

.flashapi : palign(32), run = RAM {
-l F021_API_CortexR4_BE_L2FMC_V3D16_NDS.lib(.text)
} > PBL_TXT, crc_table(tbl_CRC), table(tblFlashApi)

I'm not sure what is causing this issue.

Thank you

over 8 years ago

0 QJ Wang over 8 years ago

TI__Guru**** 199216 points

Hello Milin,

It seems to me that the code is not copied to RAM. You need to write a function to copy those flash API related function to RAM.

For example:

In cmd file:the flashAPI section contains not only the library but the bl_flash.obj and Fapi_..

flashAPI :
{
Fapi_UserDefinedFunctions.obj (.text)
bl_flash.obj (.text)
--library= ..\..\..\lib\F021_API_CortexR4_BE.lib (.text)
} load = FLASH_API, run = SRAM, LOAD_START(api_load), RUN_START(api_run), SIZE(api_size)

In asm or c file:

.def _copyAPI2RAM_
.asmfunc

_copyAPI2RAM_

.ref api_load
flash_load .word api_load
.ref api_run
flash_run .word api_run
.ref api_size
flash_size .word api_size

ldr r0, flash_load
ldr r1, flash_run
ldr r2, flash_size
add r2, r1, r2
copy_loop1:
ldr r3, [r0], #4
str r3, [r1], #4
cmp r1, r2
blt copy_loop1
bx lr

.endasmfunc

Copy the content in flashAPI section to SRAM

0 Milin P. over 8 years ago in reply to QJ Wang

Prodigy 110 points

Hey QJ,

Thanks for the response! Unfortunately, that didn't help. I verified that the run address in the map file for that section was in RAM after I made the changes you suggested. I'm not sure what bl_flash.obj and Fapi_.. are though, I don't see those objects in my project. Any other suggestions?

Thank you,

Milin

0 Milin P. over 8 years ago in reply to Milin P.

Prodigy 110 points

I did a bit more digging and found the following:

I had a watchdog kick function call in the define WAIT_FSM_READY() as so:

#define WAIT_FSM_READY() { while (FLASH_CONTROL_REGISTER->FmStat.FMSTAT_BITS.BUSY == (uint32_t)Fapi_Status_FsmBusy) {dwdKick();} }

When I removed that function call, the issues I had disappeared. I did some more digging and it seems like if I do any function calls in WAIT_FSM_READY, the prefetch exception occurs. I tried changing the code so that the watchdog kick was only during the WAIT_FSM_READY after Fapi_issueAsyncCommandWithAddress but that did not resolve my issue.

Are there any restriction on what we can do during the wait periods?

Thank you,
Milin

0 QJ Wang over 8 years ago in reply to Milin P.

TI__Guru**** 199216 points

Hello Milin,

The function in your while{} is trying to access the flash while the flash is being erased. Please copy the function related code to SRAM.

Arm-based microcontrollers

Arm-based microcontrollers forum

TMS570LC4357: Prefetch exception during erase flash using fapi