Updated: 2025/Nov/16

Please read Privacy Policy. It's for your privacy.

ATTIMER(4)                   Device Drivers Manual                  ATTIMER(4)

NAME
     attimer - AT Timer (8253) driver

SYNOPSIS
     attimer*  at acpi?
     attimer0  at isa?

DESCRIPTION
     The attimer driver handles the so-called AT Timer device, initially found
     as chip model 8253.  It is used as the main counter for the clock on the
     i386 port, but also offers control over the pitch of the PC speaker.

     The attimer driver currently only implements the access to the ISA
     register "TIMER1" which controls the pitch of the PC speaker, and should
     be configured along with pcppi(4) to be of any actual use.

SEE ALSO
     acpi(4), isa(4), pcppi(4)

NetBSD 11.99                    March 22, 2005                    NetBSD 11.99