| Title: | VAX on VMEbus: KAV30 |
| Notice: | Could have been as fast as 68K but its a VAX! |
| Moderator: | CSSVMS::KAV30_SUPP |
| Created: | Thu Apr 18 1991 |
| Last Modified: | Fri Aug 02 1996 |
| Last Successful Update: | Fri Jun 06 1997 |
| Number of topics: | 159 |
| Total number of notes: | 645 |
Hi, I received a call today from one of the EIC engineers in Merrimac. They have a customer who has a VME device that does only word transfers. They need to be able to swap the bytes and then the bits in the bytes. This is the description of mode 1 which we state is reserved to Digital. Is it possible to use mode 1? Or will the KAV30 kernel not support it? Is this something they will need to do manually in their application? Of course they would prefer to let the h/w do the swap. Any suggestions? Thanks, Alan
| T.R | Title | User | Personal Name | Date | Lines |
|---|---|---|---|---|---|
| 73.1 | HERR::CROSBIE | Fri Feb 05 1993 14:37 | 7 | ||
Hi Alan,
Mode 1 swap cannot be selected using KAV30 system services, the kernel
doesn't contain any code to set up mode 1 swap in the scatter-gather
map entry.
Graham
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| 73.2 | Thanks Graham! | ZYDECO::BODA | Realtime Products Support | Fri Feb 05 1993 19:48 | 16 |
Thanks Graham, You confirmed what was suspected. For the new KAV engineers: In some KAV30 seminar notes (done by Graham) it is mentioned that there was no practical use for this mode. However, we've had several customers run into the need for this for devices that only do word transfers. Is there some architecture restriction that prevents this from being done. Or is it a matter of the kernel setting up the S-G maps appropriately as Graham suggests in .1? Thanks, Alan | |||||