| AHD(4) | Device Drivers Manual | AHD(4) | 
ahd —
ahd* at pci? dev ? function ?
To compile in debugging code:
options AHD_DEBUG
options AHD_DEBUG_OPTS=<bitmask of options>
options AHD_REG_PRETTY_PRINTFor SCSI busses:
  
  scsibus* at ahd?
Driver features include support for narrow and wide busses, fast, ultra, ultra2, ultra160, and ultra320 synchronous transfers, packetized transfers, tagged queueing, and 512 SCBs.
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.
ahd driver supports the following:
ahd driver first appeared in
  FreeBSD 4.7 and NetBSD 2.0.
ahd driver, the AIC7xxx sequencer-code assembler,
  and the firmware running on the aic79xx chips was written by
  Justin T. Gibbs. NetBSD
  porting is done by Pascal Renauld, Frank van der Linden, Jason Thorpe, and
  Allen Briggs. This manual page is based on the
  ahc(4) manual page.
| May 16, 2009 | NetBSD 10.1 |