Architchture: FS8530 + S32R274 Configuration：S32R274 config the FS8530 by SPI，After INIT_FS Phase,

[yadi_zhang]

Architchture: FS8530 + S32R274

Configuration：S32R274 config the FS8530 by SPI，After INIT_FS Phase, The FLT_ERR_CNT was clear to 0。S32R274 config the FS8530 watchdog，the Refresh watchdog period is 1024ms，the open window is 50%。And I create a timer (period 756ms) to refresh watchdog。

Question：If S32R274 reset before refresh watchdog，After reset，The FS8530 FLT_ERR_CNT value is 1 or 3, The FS8530 BAD_WD_TIMING is 1, The FS8530 RSTB_EVENT is 1 .

If S32R274 reset after refresh watchdog, After reset, The FS8530 FLT_ERR_CNT value is 0 , The FS8530 BAD_WD_TIMING is 0, The FS8530 RSTB_EVENT is 0 .

Why the two result is diffrent?

[petervlna]

Hello,

If S32R274 reset before refresh watchdog，After reset，The FS8530 FLT_ERR_CNT value is 1 or 3, The FS8530 BAD_WD_TIMING is 1, The FS8530 RSTB_EVENT is 1 .

hmm, this seems strange. The reset is bidirectional and if there is reset on uController side then SBC is reset also.

So the watchdog will start with registers default value.

What comes to my mind is the micro did reset which will not lead to change of reset_b pin.

62.4.7 ‘Functional’ Bidirectional Reset Enable Register (RGM_FBRE) - This register enables the generation of an external reset on ‘functional’ reset. 

For example:

I am just guessing from the information you shared.

best regards,

Peter

[yadi_zhang]

Hi petervlna

        S32R274 reset by change mode to REST_DEST，Through measure the RSTB waveform，we found the diffrent result:

         1、reset after refresh watchdog，measuring one RSTB pulse waveform from S32R274

          2、reset before refresh watchdog，measuring two RSTB pulse waveform，one from S32R274， another from FS8530.

        The problem has nothing to do with S32R274，what puzzles me is FS8530，refresh FS8530 watchdog affects the result.