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/* Copyright (C) 2010 Wildfire Games.
*
* Permission is hereby granted, free of charge, to any person obtaining
* a copy of this software and associated documentation files (the
* "Software"), to deal in the Software without restriction, including
* without limitation the rights to use, copy, modify, merge, publish,
* distribute, sublicense, and/or sell copies of the Software, and to
* permit persons to whom the Software is furnished to do so, subject to
* the following conditions:
*
* The above copyright notice and this permission notice shall be included
* in all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*/
/*
* Timer implementation using 82C53/4 PIT
*/
#ifndef INCLUDED_PIT
#define INCLUDED_PIT
// note: we don't access the PIT for two reasons:
// - it rolls over every 55 ms (1.193 MHz, 16 bit) and would have to be
// read at least that often, which would require setting high thread
// priority (dangerous).
// - reading it is slow and cannot be done by two independent users
// (the second being QPC) since the counter value must be latched.
//
// there are enough other counters anway.
static const i64 PIT_FREQ = 1193182; // (= master oscillator frequency/12)
#endif // #ifndef INCLUDED_PIT
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