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* [U-Boot-Users] errata CPU10 for MPC855 ?
@ 2003-02-05 16:17 Steven Scholz
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From: Steven Scholz @ 2003-02-05 16:17 UTC (permalink / raw)
  To: u-boot

Hi there,

I just stumbled over an old errata:

CPU10. Possible Excess Current Consumption in Deep Sleep Mode.

Certain nodes of the multiplier hardware are not initialized at reset, and may 
thus result in non-destructive internal contention. As a result, if the 
processor is put into Deep Sleep mode without first putting the multiplier
into a known state, current consumption in this mode may be higher than expected.

Workaround:
Execute a mullw instruction at any point after reset; this will put the internal 
nodes in an orderly state. Deep Sleep mode may then be entered at any time 
thereafter.

The only mullw's I found in post/cpu/asm.S.

I am not sure, but I guess these functions will only get called if I enable POST!?

So should we put "a mullw instruction at any point after reset"???

Thanks,

Steven

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2003-02-05 16:17 [U-Boot-Users] errata CPU10 for MPC855 ? Steven Scholz

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