Watchdog operation during FLASH erase

[yixinwu]

Hello community,

Now we are using the combination of MPC5744P and MC33907. The companion chip has a watchdog, which should be updated by the processor. The time window has been set as 32ms for example. We have also used the driver code from NXP (function as a hex constant) for FLASH erase, so we cannot put the watchdog update routine into this function, which means, during FLASH erase the watchdog cannot be updated.

A consideration is, the watchdog time window can be enlarged before FLASH erase and can be shortened after it. But the FLASH erase could take longer than 1 second, so the watchdog may not be updated even the largest time window for watchdog is used (1024ms). Is there any other (better) solution or suggestion? Thanks.

[petervlna]

Hi,

Usually you do not erase whole flash at once, but you erase flash by blocks and you do update of watchdog between blocks erases.

I don't think that is safe to enlarge watchdog during flash erase and MPC5744P is safety class micro. As I am not familiar with your application and its requirements I can only recommend you to do flash erase by blocks and update watchdog between the erases.

Peter

[yixinwu]

Thank you for your reply!

Is there any sample code available how FLASH can be erased by blocks? Now I have something like this:

const UINT32 FlashErase_C[] =
{ 
    0x182106D0, 0x00801B01, 0x0910DD01, 0x480FC0E3, 0x7480063F,
    0x67E0C0CE, 0xE603CCD3, 0xE802C1D3, 0x67BCE206, 0x67DCE607, 
......

}

[petervlna]

Hi,

Now I got info from colleague that there is callback function exactly for this reason.

It is described in drivers manual.

Peter

[yixinwu]

Could you please share this drivers manual? Because this code is adapted from some old source, I can't find the manual any more.

[petervlna]

Hi,

You can just easily download whole driver with documentation from our web site...

http://www.nxp.com/assets/downloads/data/en/device-drivers/C55_JDP_SSD.exe 

Peter

[yixinwu]

Thank you very much.

I have checked the manual and the function FlashErase and the config of SSD is defined like this:

UINT32 FlashErase ( PSSD_CONFIG pSSDConfig,
                    UINT8 eraseOption,
                    UINT32 lowBlockSelect,
                    UINT32 midBlockSelect,
                    UINT32 highBlockSelect,
                    N256K_BLOCK_SEL n256KBlockSelect
                    );

typedef struct _c55_ssd_config

{

UINT32 c55RegBase;

UINT32 mainArrayBase;

BLOCK_INFO lowBlockInfo;

BLOCK_INFO midBlockInfo;

BLOCK_INFO highBlockInfo;

UINT32 n256KBlockNum;

UINT32 uTestArrayBase;

BOOL mainInterfaceFlag;

UINT32 programmableSize;

BOOL BDMEnable;

} SSD_CONFIG, *PSSD_CONFIG;

I don't understand how a callbak function can be transferred when I use this function.

In our last generation of product we have used MPC5533 and in the source code I find the FlashErase is defined like this:

typedef UINT32 (*pFLASHERASE) (
                PSSD_CONFIG pSSDConfig,
                BOOL shadowFlag,
                UINT32 lowEnabledBlocks,
                UINT32 midEnabledBlocks,
                UINT32 highEnabledBlocks,
                void (*CallBack)(void)
               );

There was this transfer of CallBack function.

[petervlna · Accepted solution]

Ok,

Here is example of callback function. It is for different micro, but I hope you can understand it. It will be same also for your micro.

Peter

[yixinwu]

I have figured out, that we have done FlashCheckStatus immediately after FlashErase. The status check has costet a long time, which kills my watchdog rountine. Now I do the status check with a time delay and the problem should be solved now. Thank you very much for your support.