vme_tsi148 question

[Martyn Welch]

On 14/01/14 04:07, Michael Kenney wrote:
> Unfortunately, the results are the same. I'm running this from home so
> I'll have to confirm with the logic-analyzer tomorrow but the bridge
> driver error messages suggest the same D8 writes (which for some
> reason our A/D board does not like). 

The hardware probably doesn't support 8-bit reads/writes, from memory, it
doesn't have to according to the spec.

> Here's a dmesg excerpt:
> 
> [ 5631.810902] vme_tsi148 0000:02:02.0: VME Bus Error at address:
> 0x508000, attributes: 8008b900
> [ 5631.810972] vme_tsi148 0000:02:02.0: VME Bus Exception Overflow Occurred
> [ 5631.810977] vme_tsi148 0000:02:02.0: VME Bus Error at address:
> 0x508001, attributes: c0087900
> [ 5631.810991] vme_tsi148 0000:02:02.0: VME Bus Error at address:
> 0x508003, attributes: 80087900
> [ 5631.811061] vme_tsi148 0000:02:02.0: VME Bus Exception Overflow Occurred
> 
> The register that I am trying to write occupies 4 bytes starting at
> 0x508000. I have verified that the value I am trying to write to the
> register is 4-byte aligned. I'm essentially doing the following:
> 
> uint32_t value;
> pwrite(window_fd, &value, sizeof(value), 0x508000);
> 

How have you setup the window? The offset is relative to the window you have
configured, so if that doesn't start at 0x0, then you aren't writing where you
think you are.

> Window is configured for A24 and D32.
> 
> Does the "attributes" value from the tsi148 provide any further clues?
> 

Not really - it gives the status of some of the VME lines when the error
occurred (Address lines, data strobes), it says that there was an error, in
one case it shows an exception overflow and that it happened on the VME bus.

Martyn

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