Article View: comp.sys.next.programmer
Article #824Re: Finding how much DSP56001 RAM is installed via program??
From: Michael van Elst
Date: Thu, 27 Aug 1992 12:38
Date: Thu, 27 Aug 1992 12:38
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1558 bytes
In <17fb61INN572@agate.berkeley.edu> izumi@pinoko.berkeley.edu (Izumi Ohzawa) writes:
>TestLoop
> move #>$5a5a5a,b ;load test pattern
> move b,x:(R0) ;write to a memory loc
> move x:(R0)+,a ;read back into A1, post-incr address.
> cmp a,b
> jne memory_fail
Due to bus capacitance the read back will most often read the previously
written value. You can circumvent that by writing a different value to a
different address in between. F.e.:
move #>$5a5a5a,x0
move #>$272727,x1
...
move x0,x:(r0)+
move x1,x:(r0)- ; dummy write to next cell (make sure that this
; doesn't cause problems at the end of your memory)
move x:(r0)+,a
eor x0,a
jne memory_fail
Regards,
--
Michael van Elst
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Newsgroups: comp.sys.next.programmer,comp.dsp Path: arc1-ca.pugleaf.net!sparky!uunet!mcsun!Germany.EU.net!mpifr-bonn.mpg.de!speckled.mpifr-bonn.mpg.de!mlelstv From: mlelstv@speckled.mpifr-bonn.mpg.de (Michael van Elst) Subject: Re: Finding how much DSP56001 RAM is installed via program?? Message-ID: <1992Aug27.123806.19051@mpifr-bonn.mpg.de> Keywords: DSP, 56001, NeXT Sender: news@mpifr-bonn.mpg.de Nntp-Posting-Host: speckled Organization: Max-Planck-Institut f"ur Radioastronomie References: <1992Aug26.060638.10407@ee.ubc.ca> <17fb61INN572@agate.berkeley.edu> Date: Thu, 27 Aug 1992 12:38:06 GMT Lines: 31