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Why RAM and System RAM shall be reset when system boot up?

swu.1
Associate II

Hi expert,

I am using Stellar SR6 P7 line, e.g. SR6P7C8. According to the SDK there is RAM and System RAM reset operation when system boot,

/* Initialize memories protected by ECC */
    bl _raminit
    bl _sysraminit

I want to get more information about clearing memories for ECC. Why these step are needed? Is this for DAN-0055942?

Thanks.

1 ACCEPTED SOLUTION

Accepted Solutions

>>Why these step are needed?

Well presumably the MCU can start with all manner of random bits in the data lines and the ecc/hamming bits. Odds are just reading memory will result in a fault.

You zero memory to establish a workable baseline, because the system doesn't clear the memory automatically.

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4 REPLIES 4

>>Why these step are needed?

Well presumably the MCU can start with all manner of random bits in the data lines and the ecc/hamming bits. Odds are just reading memory will result in a fault.

You zero memory to establish a workable baseline, because the system doesn't clear the memory automatically.

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Up vote any posts that you find helpful, it shows what's working..
swu.1
Associate II

Thanks for your update.

CAyde.1
Associate

Resetting RAM and system RAM during system boot up helps to clear any leftover data or instructions that may be stored in memory from previous sessions or processes. This ensures that the system starts with a clean slate and is not affected by any stray data or instructions that could cause errors or instability. Additionally, resetting RAM can help to optimize system performance by freeing up memory that may have been occupied by unnecessary or outdated data.

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Giuseppe DI-GIORE
ST Employee

The RAM is protected by Error Code Correction (ECC).

In order to start ECC, the RAM has to be set to a known value on startup, usually zero.

Just for introduction to ECC, see AN4276.

Regards,

Giuseppe