AHD(4) | Device Drivers Manual | AHD(4)

# NAME

`ahd` — Adaptec PCI/PCI-X AIC79xx-based Ultra320 SCSI interface

# SYNOPSIS

`ahd* at pci?`

# DESCRIPTION

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

`ahd` supports narrow and wide buses; synchronous and asynchronous operation; fast, ultra, ultra2, ultra160, and ultra320 (packetized) transfers; tagged queuing and 512 SCBs.

`ahd` does not support target mode operation.

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

To compile in debugging code:

`option AHD_DEBUG` `option AHD_DEBUG_OPTS=<bitmask of options>`

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

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

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

# HISTORY

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

# AUTHORS

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.

August 14, 2012 | Debian