1.\" $NetBSD: attimer.4,v 1.2 2007/09/10 10:35:52 cube 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.\" 3. Neither the name of The NetBSD Foundation nor the names of its 15.\" contributors may be used to endorse or promote products derived 16.\" from this software without specific prior written permission. 17.\" 18.\" THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 19.\" ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 20.\" TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 21.\" PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 22.\" BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 23.\" CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 24.\" SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 25.\" INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 26.\" CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 27.\" ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 28.\" POSSIBILITY OF SUCH DAMAGE. 29.\" 30.Dd March 22, 2005 31.Os 32.Dt ATTIMER 4 33.Sh NAME 34.Nm attimer 35.Nd AT Timer (8253) driver 36.Sh SYNOPSIS 37.Cd "attimer* at acpi?" 38.Cd "attimer0 at isa?" 39.Sh DESCRIPTION 40The 41.Nm 42driver handles the so-called AT Timer device, initially found as chip 43model 8253. 44It is used as the main counter for the clock on the i386 port, 45but also offers control over the pitch of the PC speaker. 46.Pp 47The 48.Nm 49driver currently only implements the access to the ISA register 50.Dq TIMER1 51which controls the pitch of the PC speaker, 52and should be configured along with 53.Xr pcppi 4 54to be of any actual use. 55.Sh SEE ALSO 56.Xr acpi 4 , 57.Xr isa 4 , 58.Xr pcppi 4 59