| 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 | 
    Hello,
    
    This is about a VME300 board but it can be related to a KAV30. A
    customer observed that DMA done by EZDRIVER could last 18 microsec
    causing other boards accessing the DPRAM a bus error. He said
    that the specs should give 6 microsec. for DMA bursts at most.
    
    My question is how to decrease this DMA bus timing by the EZDRIVER
    for other boards not experiencing fatal bus errors ?
    
    Thank you in advance.
    Best regards,
    Philippe
| T.R | Title | User | Personal Name | Date | Lines | 
|---|---|---|---|---|---|
| 146.1 | bad luck... | EICMFG::KAV30_SUPP | Thu Dec 08 1994 13:30 | 9 | |
|     Hi Phillipe,
    
    that is - unfortunately - a known problem, and if you use ELN and
    DECnet there is nothing you can do. 6 microseconds is the chip spec,
    18 microseconds is what the EZdriver does.... You could ask the
    ELN guys if they have a solution/fix/workaround... we have not heard of
    anything in this direction....
    
    Thomas
 | |||||
| 146.2 | see VAXELN conference | SWTHOM::VOUTERS | Mon Dec 12 1994 14:42 | 2 | |
|     Posted in VAXELN Notesfile.
    Philippe
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