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


     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



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

     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

     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.


     The ahd driver supports the following:

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


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


     The ahd driver first appeared in FreeBSD 4.7.


     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.


     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.