NAME    [Toc]    [Back]

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

SYNOPSIS    [Toc]    [Back]

     For one or more PCI/PCI-X cards:
	   device pci
	   device ahd

     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>

     For one or more SCSI busses:
	   device scbus

DESCRIPTION    [Toc]    [Back]

     This driver provides access to the SCSI bus(es) connected to Adaptec
     AIC7901 and AIC7902 host adapter chips.  These chips are found on many
     motherboards as well as the 29320 and 39320 Adaptec SCSI controller
     cards.

     Driver features include support for narrow and wide busses, fast, ultra,
     ultra2, ultra160, and ultra320 synchronous transfers, packetized transfers,
 tagged queueing, 512 SCB's, and target mode.

     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 adapter's SCSI ID.

BUGS    [Toc]    [Back]

     The current generation of 79xx chips do not support target mode in
     Ultra320 mode.  Target mode in general has not been well tested in this
     driver.

SEE ALSO    [Toc]    [Back]

     ahc(4), cd(4), da(4), sa(4), scsi(4)

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.  This manual
     page is based on the ahc(4) manual page.

HISTORY    [Toc]    [Back]

     The ahd driver first appeared in FreeBSD 4.7.


FreeBSD 5.2.1		       September 1, 2002		 FreeBSD 5.2.1