1.\" $NetBSD: attimer.4,v 1.4 2009/03/09 19:24:28 joerg Exp $ 2.\" 3.\" Copyright (c) 2005 The NetBSD Foundation. 4.\" All rights reserved. 5.\" 6.\" Redistribution and use in source and binary forms, with or without 7.\" modification, are permitted provided that the following conditions 8.\" are met: 9.\" 1. Redistributions of source code must retain the above copyright 10.\" notice, this list of conditions and the following disclaimer. 11.\" 2. Redistributions in binary form must reproduce the above copyright 12.\" notice, this list of conditions and the following disclaimer in the 13.\" documentation and/or other materials provided with the distribution. 14.\" 15.\" THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 16.\" ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 17.\" TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 18.\" PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 19.\" BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 20.\" CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 21.\" SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 22.\" INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 23.\" CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 24.\" ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 25.\" POSSIBILITY OF SUCH DAMAGE. 26.\" 27.Dd March 22, 2005 28.Dt ATTIMER 4 29.Os 30.Sh NAME 31.Nm attimer 32.Nd AT Timer (8253) driver 33.Sh SYNOPSIS 34.Cd "attimer* at acpi?" 35.Cd "attimer0 at isa?" 36.Sh DESCRIPTION 37The 38.Nm 39driver handles the so-called AT Timer device, initially found as chip 40model 8253. 41It is used as the main counter for the clock on the i386 port, 42but also offers control over the pitch of the PC speaker. 43.Pp 44The 45.Nm 46driver currently only implements the access to the ISA register 47.Dq TIMER1 48which controls the pitch of the PC speaker, 49and should be configured along with 50.Xr pcppi 4 51to be of any actual use. 52.Sh SEE ALSO 53.Xr acpi 4 , 54.Xr isa 4 , 55.Xr pcppi 4 56