Interphase EISA adaptor does not support EISA bus preemption (161721)
The information in this article applies to:
- Microsoft Windows NT Workstation 3.5
- Microsoft Windows NT Workstation 3.51
- Microsoft Windows NT Workstation 4.0
- Microsoft Windows NT Server 3.5
- Microsoft Windows NT Server 3.51
- Microsoft Windows NT Server 4.0
This article was previously published under Q161721 SYMPTOMS The Cisco/Interphase EISA FDDI/CDDI adaptors do not support
EISA bus preemption. This may cause
the adaptor to
be incompatible with computers by
using a dual/split PCI/EISA I/O bus. The
following models of Cisco/Interphase EISA FDDI/CDDI network adaptors:
- WA-C321T-PC
- WA-C323T-PC
- WA-C326T-PC
- WA-C328T-PC
can cause intermittent system resets or crashes with STOP:
0X0000000A. Some personal
computer
systems that are known to exhibit this symptom include
the following:
- IBM PC Server 320 CYO
- Compaq Proliant series (some models)
- ALR Revolution Quad6
CAUSEThe
Cisco System Workgroup Business Unit has discovered that its EISA FDDI/CDDI
adaptor does not comply with the EISA Bus Preemption as described by the EISA
Specification 3.12.
The Cisco EISA FDDI/CDDI adaptor does not support
EISA bus preemption. This causes the adaptor to be incompatible with
computers that have a dual or split EISA/PCI I/O bus.
The
Interphase EISA FDDI/CDDI adaptor
requires guaranteed access time (GAT) to function correctly.
Personal
computers
that implement EISA bus preemption without also supporting GAT will experience
problems. The symptom is intermittent and occurs when both the FDDI adaptor
and a PCI device are active.
The adaptor
design predates implementation of the EISA bus preemption feature as described
in EISA specification 3.12 (PCI/EISA systems shipped after 9/1/95).
In personal
computers with both a PCI and an EISA bus, PCI devices
are allowed access to system memory even if the EISA bus has been granted
control. Because the adaptor
requires GAT, and because PCI devices are able to de-assert the EXRDY (external
ready) signal to the EISA bus, the adaptor
will stall and not finish its transfer to memory.
The
WA-C321T-PC adaptor is on the Windows NT Hardware Compatible List (HCL) and the
driver is available on the \DRVLIB\NETCARD\operating
system\C320NT directory of the Windows NT Server and Workstation
compact discs.
Note Here, operating system is the placeholder for the name of
the operating system.WORKAROUND If you are experiencing this problem, first contact your
system vendor to see if the
personal computer supports GAT mode. If the
personal
computer
does not support GAT, consider the following two workarounds:
- Reduce adaptor
transfer burst size from 64 bytes to 32 bytes. This reduces burst transfer time
and has a positive effect on some systems. This can be changed in the registry
entries for the drivers (C320tnt.sys). To make this change, follow the steps
listed below:
Warning Using Registry Editor incorrectly can cause
serious, system-wide problems that may require you to reinstall Windows NT to
correct them. Microsoft cannot guarantee that any problems resulting from the
use of Registry Editor can be solved. Use this tool at your own risk.
- Run Regedt32 and select the HKEY_LOCAL_MACHINE
Window
- Go to
SYSTEM\CurrentControlSet\Services\c320tnt1\parameters
- Change the "BurstSize" from 63 (3F hex) to 31 (1F hex)
- An alternative for adding FDDI connectivity, for systems
with PCI slots, is the Interphase PCI/FDDI 5511.
Note Do
not
use an EISA adaptor
in personal
computers with active PCI devices. Use the adaptor
only in personal
computers
that have an EISA bus.
| Modification Type: | Major | Last Reviewed: | 12/22/2005 |
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| Keywords: | kb3rdparty kbHardware KB161721 |
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