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HPET(4) NetBSD/x86 Kernel Interfaces Manual HPET(4)
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hpet -- High Precision Event Timer
hpet* at acpihpetbus?
hpet* at acpinodebus?
hpet* at amdpcib?
hpet* at ichlpcib?
The hpet driver supports High Precision Event Timers (HPETs). The HPET
architecture defines one main 64-bit counter and several additional
timers with variable width. The minimum clock frequency of the main
timecounter is 10 MHz, but much higher rates are common. The additional
32 or 64 -bit parts are typically accessible via MMIO that is set by the
system BIOS through ACPI.
As a HPET can provide higher interrupt rates than a RTC or attimer(4),
multimedia is one typical application context. The interrupt logic is
configurable through I/O APIC, but a legacy mode is provided for older
acpi(4), attimer(4), timecounter(9), tsc(9)
Intel Corporation, IA-PC HPET (High Precision Event Timers)
Specification, Revision 1.0a,
http://www.intel.com/hardwaredesign/hpetspec_1.pdf, October, 2004.
NetBSD 7.1.2 June 14, 2011 NetBSD 7.1.2