hpet(4) - NetBSD Manual Pages

HPET(4)               NetBSD/x86 Kernel Interfaces Manual              HPET(4)


NAME

     hpet -- High Precision Event Timer


SYNOPSIS

     hpet* at acpihpetbus?
     hpet* at acpinodebus?
     hpet* at amdpcib?
     hpet* at ichlpcib?


DESCRIPTION

     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
     systems.


SEE ALSO

     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 9.3                       June 14, 2011                      NetBSD 9.3