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authorbrueffer <brueffer@FreeBSD.org>2014-06-03 19:25:39 +0000
committerbrueffer <brueffer@FreeBSD.org>2014-06-03 19:25:39 +0000
commit51dec3635e1a027aec8c485bfb56b79a1b62f8fb (patch)
tree6cf742bf2804f686149a44f89603a211cc48bb2e /share
parent9def490ad1703fb10c00235aa158e73a926df4af (diff)
downloadFreeBSD-src-51dec3635e1a027aec8c485bfb56b79a1b62f8fb.zip
FreeBSD-src-51dec3635e1a027aec8c485bfb56b79a1b62f8fb.tar.gz
MFC: r266709
Language cleanup. Reviewed by: mav, bcr, wblock
Diffstat (limited to 'share')
-rw-r--r--share/man/man4/attimer.442
1 files changed, 26 insertions, 16 deletions
diff --git a/share/man/man4/attimer.4 b/share/man/man4/attimer.4
index 751b9ea..097e073 100644
--- a/share/man/man4/attimer.4
+++ b/share/man/man4/attimer.4
@@ -24,7 +24,7 @@
.\"
.\" $FreeBSD$
.\"
-.Dd September 14, 2010
+.Dd May 26, 2014
.Dt ATTIMER 4
.Os
.Sh NAME
@@ -37,38 +37,48 @@ The following tunables are settable from the
.Xr loader 8 :
.Bl -ohang
.It Va hint.attimer. Ns Ar X Ns Va .clock
-controls event timers functionality support. Setting to 0, disables it.
-Default value is 1.
+controls support for the event timer functionality.
+Setting this value to
+.Dv 0
+disables it.
+The default value is
+.Dv 1 .
.It Va hint.attimer. Ns Ar X Ns Va .timecounter
-controls time counter functionality support. Setting to 0, disables it.
-Default value is 1.
+controls support for the time counter functionality.
+Setting this value to
+.Dv 0
+disables it.
+The default value is
+.Dv 1 .
.It Va hw.i8254.freq
-allows to override default counter frequency.
-The same value is also available in run-time via
+allows overriding the default counter frequency.
+The same value is also available at run-time via the
.Va machdep.i8254_freq
sysctl.
.El
.Sh DESCRIPTION
This driver uses i8254 Programmable Interval Timer (AT Timer) hardware
-to supply kernel with one time counter and one event timer, and generate
-sound tones for system speaker.
+to supply the kernel with one timecounter and one event timer, and to generate
+sound tones for the system speaker.
This hardware includes three channels.
-Each channel includes 16bit counter, counting down with known,
+Each channel includes a 16 bit counter which decreases with a known,
platform-dependent frequency.
Counters can operate in several different modes, including periodic and
one-shot.
-Output of each channel has platform-defined wiring: one channel is wired
+The output of each channel has platform-defined wiring: one channel is wired
to the interrupt controller and may be used as event timer, one channel is
-wired to speaker and used to generate sound tones, and one timer is reserved
+wired to the speaker and used to generate sound tones, and one timer is reserved
for platform purposes.
.Pp
-Driver uses single hardware channel to provide both time counter and event
+The
+.Nm
+driver uses a single hardware channel to provide both time counter and event
timer functionality.
-To make it possible, respective counter must be running in periodic more.
-As result, one-shot event timer mode supported only when time counter
+To make this possible, the respective counter must be running in periodic mode.
+As a result, the one-shot event timer mode is supported only when time counter
functionality is disabled.
.Pp
-Event timer provided by the driver is irrelevant to CPU power states.
+The event timer provided by the driver is irrelevant to CPU power states.
.Sh SEE ALSO
.Xr apic 4 ,
.Xr atrtc 4 ,
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