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Fault flag clearing behavior of FS6500

Hi team,

I have a question regarding the fault flag clearing behavior of FS6500.

According to the datasheet, the LPOOF (bit0) and DFS (bit1) flags inside the MODE register (address 0x15) shall be cleared only by Power-on reset or register read operation.

However, from my hardware test:

Writing to the MODE register also clears LPOOF and DFS fault bits unexpectedly.

There is no description in the datasheet mentioning that write access can clear these status flags.

Could you help explain the root cause for this phenomenon?

Is this intended silicon behavior or undocumented side effect?

Thanks & Best regards

DEVKIT-MPC5744P FS6500

Re: Fault flag clearing behavior of FS6500

Hello,

Check you write instruction.

In most software drivers, a register write is implemented as a read-modify-write (RMW) sequence.

If the datasheet specifies that reading MODE clears LPOOF/DFS, then the flags may already be cleared during the read phase. The subsequent write merely creates the impression that the write operation caused the clearing.

Best regards,

Peter