AHD(4)							   BSD Kernel Interfaces Manual 						    AHD(4)

NAME

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

SYNOPSIS

     To compile this driver into the kernel, place the following lines in your kernel configuration file:

	   device pci
	   device scbus
	   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>

     Alternatively, to load the driver as a module at boot time, place the following line in loader.conf(5):

	   ahd_load="YES"

DESCRIPTION

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

     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/asyn-
     chronous transfers, maximum synchronous negotiation rate, wide transfers, disconnection, and the host adapter's SCSI ID.

HARDWARE

     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

SEE ALSO

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

HISTORY

     The ahd driver first appeared in FreeBSD 4.7.

AUTHORS

     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.

BUGS

     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.

BSD
								   July 4, 2004 							       BSD