Eric Bjorklund wrote:
> .
>
> In my experience I have usually been able to always get non-DMA drivers to work by always declaring the register pointer as "volatile" (which is more to defeat compiler optimization and not really a caching issue) and following the last write with a dummy read to the same register (to flush the pipeline).
Do you mean the dummy read following the last write is needed for
only vxWorks-mvme5500 ? Or is it needed for almost all the powrPC
boards using VxWorks ? Does it apply to all the VME boards ?
Is this implemented in other vxWorks-PPC site such as APS or any other
facility ? I did'nt notice this in synApp which was written by APS, but I am
off-site now that I can'nt verify the code.
>
>
> DMA devices are another story. For these it would be nice to have devLib routines to do cache invalidation and flushing. Byte order is another issue. For non-DMA devices, however, I don't think caching is a problem.
At NSLS, we use RTEMS-MVME5500 BSP that I developed, which
enables the hardware cache snoop on CPU local memory for all the
DMA applications so that the sofware caching is not needed yet.
However, the VME space is marked as Non-Cacheable and
Guarded in the BSP.
Regards,
Kate
- Replies:
- Re: Dev lib off-board register access Andrew Johnson
- Re: Dev lib off-board register access Eric Bjorklund
- RE: Dev lib off-board register access Rees, NP (Nick)
- References:
- Dev lib off-board register access Rees, NP (Nick)
- Re: Dev lib off-board register access Dirk Zimoch
- Re: Dev lib off-board register access Eric Bjorklund
- Navigate by Date:
- Prev:
Accumulated beam current of 1mA, at an energy of 3GeV (First Light) at the Australian Synchrotron Richard Farnsworth
- Next:
Re: Dev lib off-board register access Andrew Johnson
- Index:
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
2005
<2006>
2007
2008
2009
2010
2011
2012
2013
2014
2015
2016
2017
2018
2019
2020
2021
2022
2023
2024
- Navigate by Thread:
- Prev:
Re: Dev lib off-board register access Eric Bjorklund
- Next:
Re: Dev lib off-board register access Andrew Johnson
- Index:
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
2005
<2006>
2007
2008
2009
2010
2011
2012
2013
2014
2015
2016
2017
2018
2019
2020
2021
2022
2023
2024
|