ADW(4) BSD Kernel Interfaces Manual ADW(4)NAMEadw — Advansys PCI 16bit SCSI Host adapter driver
SYNOPSIS
device pci
device adw
For one or more SCSI busses:
device scbus0 at adw0
To allow PCI adapters to use memory mapped I/O if enabled:
options ADW_ALLOW_MEMIO
DESCRIPTION
This driver provides access to the 16bit SCSI bus connected to the
Advanced Systems Products, Inc. ASC3550 Ultra, and ASC38C0800 Ultra2,
SCSI Host Adapter chips. AdvanSys products incorporating these chips
include the ABP[3]940UW, ABP950UW, ABP970UW, ABP3940U2W, and ABP3950U2W.
Both chips support, synchronous transfers (20MHz and 40MHz max respec‐
tively), 16bit transfers, tagged queueing, and up to 253 concurrent SCSI
transactions.
Per target configuration performed in the AdvanceWare menu, which is
accessible at boot, is honored by this driver. This includes synchro‐
nous/asynchronous transfers, maximum synchronous negotiation rate, wide
transfers, disconnection, tagged queueing, and the host adapter's SCSI
ID. The global setting for the maximum number of tagged transactions
allowed per target is not honored as the CAM SCSI system will automati‐
cally determine the maximum number of tags a device can receive as well
as guarantee fair resource allocation among devices.
Memory mapped I/O can be enabled with the “ADW_ALLOW_MEMIO” configuration
option. Memory mapped I/O is more efficient than the alternative, pro‐
grammed I/O. Most PCI BIOSes will map devices so that either technique
for communicating with the card is available.
SEE ALSOadv(4), cd(4), da(4), sa(4), scsi(4)HISTORY
The adw driver appeared in FreeBSD 3.0.
AUTHORS
The adw driver was ported by Justin T. Gibbs from the Linux driver writ‐
ten by Bob Frey of Advanced System Products, Inc. Many thanks to Advan‐
Sys for providing the original driver under a suitable license for use in
FreeBSD.
BSD September 29, 2007 BSD
