On Thu, 3 Apr 2008, Stephen D. Barnes wrote:

> The following code is from the MPLab template for the dsPIC30F2010.
> Watching the W14 reg and running mpsim, W14 does pre-increments and
> throught the REPEAT loop
> achieves a value of 0x001A then is cleared to zero. What purpose does
> this serve?
>
> _wreg_init:
>        CLR W0
>        MOV W0, W14
>        REPEAT #12
>        MOV W0, [++W14]
>        CLR W14
>        RETURN

It prevents buggy code from generating an uninitialized W register
reset, which is caused by using an uninitialized W register as an
address.  This code pretty much defeats the whole point of the
uninitialized W register reset feature.

--
John W. Temples, III
-- 
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