NAME    [Toc]    [Back]

     ahd - Adaptec PCI/PCI-X  AIC79xx-based  Ultra320  SCSI  host
adapter driver

SYNOPSIS    [Toc]    [Back]

     ahd* at pci? dev ? function ?
     scsibus* at ahd?

DESCRIPTION    [Toc]    [Back]

     This driver provides access to the SCSI bus(es) connected to
Adaptec
     AIC79xx host adapter chips.

     Driver features include support for narrow and  wide  buses,
fast, ultra,
     ultra2, ultra160, and ultra320 synchronous transfers, packetized transfers,
 tagged queuing, 512 SCBs, and target mode.

     The ahd driver supports the following:

           +o   Adaptec AIC7901 host adapter chip
           +o   Adaptec AIC7901A host adapter chip
           +o   Adaptec AIC7902 host adapter chip
           +o   Adaptec 29320 host adapter
           +o   Adaptec 39320 host adapter
           +o   Many motherboards with on-board SCSI support

     To compile in debugging code:

           options AHD_DEBUG
           options AHD_DEBUG_OPTS=<bitmask of options>
           options AHD_REG_PRETTY_PRINT

     To configure one or more controllers to  assume  the  target
role:

           options AHD_TMODE_ENABLE=<bitmask of units>

     The  AHD_DEBUG_OPTS option is used to control which diagnostic messages
     are printed to the console when AHD_DEBUG is enabled.  Logically OR the
     following bits together:

           Value    Function
           0x0001   Show miscellaneous information
           0x0002   Show sense data
           0x0004   Show Serial EEPROM contents
           0x0008   Show bus termination settings
           0x0010   Show host memory usage
           0x0020   Show SCSI protocol messages
           0x0040   Show mode pointer of the chip register window
           0x0080   Show selection timeouts
           0x0100   Show FIFO usage messages
           0x0200   Show Queue Full status
           0x0400   Show SCB queue status
           0x0800   Show inbound packet information
           0x1000   Show S/G list information
           0x2000   Enable extra diagnostic code in the firmware

     The AHD_REG_PRETTY_PRINT option compiles in support for  human-readable
     bit definitions for each register that is printed by the debugging code.
     However, it also bloats the compiled size of the  driver  by
approximately
     215KB.

     Individual  controllers  may be configured to operate in the
target role
     through the AHD_TMODE_ENABLE configuration option.  The value assigned to
     this  option  should  be  a bitmap of all units where target
mode is desired.
     For example, a value of 0x25 would  enable  target  mode  on
units 0, 2, and
     5.   Note  that  target  mode is only supported for ultra160
speeds and below.


     Per target configuration performed in the SCSI-Select  menu,
accessible at
     boot,  is  honored  by  this  driver.   This  includes  synchronous/asynchronous
     transfers, maximum synchronous negotiation rate, wide transfers, disconnection,
 and the host adapters SCSI ID.

SEE ALSO    [Toc]    [Back]

     ahc(4),  cd(4),  ch(4),  intro(4),  pci(4),  scsi(4), sd(4),
st(4), uk(4)

HISTORY    [Toc]    [Back]

     The ahd driver was ported from FreeBSD  4.7  and  first  appeared in OpenBSD
     3.6.

AUTHORS    [Toc]    [Back]

     The  ahd  driver,  the AIC7xxx sequencer-code assembler, and
the firmware
     running on the aic79xx chips was written by Justin T. Gibbs.

     OpenBSD port by Milos Urbanek, Kenneth R. Westerback & Marco
Peereboom.

BUGS    [Toc]    [Back]

     The current generation of 79xx chips do not  support  target
mode in Ultra320
  mode.   In this driver all target mode code has been
commented out.

     Currently there are issues with drives that run slower  than
U320 speeds.

OpenBSD      3.6                           July      5,      2004