Universe VME notes (was Re: BSP for Motorola MVME5500)
feng at bnl.gov
Thu Apr 15 19:23:56 UTC 2004
Till Straumann wrote:
> You would have to either disable posted writes (incurring
> a significant performance penalty) altogether or set up
> secondary VME windows with PWEN cleared. This would be more
> elegant but doesn't fit the EPICS devLib API.
I had tried to disable the posted writes prio to 'write probes', and
reenabled the posted writes after 'write probes' to avoid
the performance penalty. However, it did not work.
> 2) Some hardware (such as the MPC106 hostbride on my SVGM board)
> doesn't even bother to support raising machine check exceptions
> on failing VME writes.
Ditto MVME5500. The EMCP signal is pulled up high and not used.
> It is recommended to exclusively use 'read probes' for device detection.
Great! This takes out one struggle from my TODOs.
Thanks a lot,
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