2 * Copyright (c) 2004, 2005
3 * The Regents of The University of Michigan
6 * This code is part of the M5 simulator.
8 * Permission is granted to use, copy, create derivative works and
9 * redistribute this software and such derivative works for any
10 * purpose, so long as the copyright notice above, this grant of
11 * permission, and the disclaimer below appear in all copies made; and
12 * so long as the name of The University of Michigan is not used in
13 * any advertising or publicity pertaining to the use or distribution
14 * of this software without specific, written prior authorization.
16 * THIS SOFTWARE IS PROVIDED AS IS, WITHOUT REPRESENTATION FROM THE
17 * UNIVERSITY OF MICHIGAN AS TO ITS FITNESS FOR ANY PURPOSE, AND
18 * WITHOUT WARRANTY BY THE UNIVERSITY OF MICHIGAN OF ANY KIND, EITHER
19 * EXPRESS OR IMPLIED, INCLUDING WITHOUT LIMITATION THE IMPLIED
20 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
21 * PURPOSE. THE REGENTS OF THE UNIVERSITY OF MICHIGAN SHALL NOT BE
22 * LIABLE FOR ANY DAMAGES, INCLUDING DIRECT, SPECIAL, INDIRECT,
23 * INCIDENTAL, OR CONSEQUENTIAL DAMAGES, WITH RESPECT TO ANY CLAIM
24 * ARISING OUT OF OR IN CONNECTION WITH THE USE OF THE SOFTWARE, EVEN
25 * IF IT HAS BEEN OR IS HEREAFTER ADVISED OF THE POSSIBILITY OF SUCH
28 * Authors: Ali G. Saidi
33 #include "base/misc.hh"
34 #include "dev/intel_8254_timer.hh"
38 Intel8254Timer::Intel8254Timer(EventManager
*em
, const string
&name
,
39 Counter
*counter0
, Counter
*counter1
, Counter
*counter2
) :
40 EventManager(em
), _name(name
)
42 counter
[0] = counter0
;
43 counter
[1] = counter1
;
44 counter
[2] = counter2
;
47 Intel8254Timer::Intel8254Timer(EventManager
*em
, const string
&name
) :
48 EventManager(em
), _name(name
)
50 counter
[0] = new Counter(this, name
+ ".counter0", 0);
51 counter
[1] = new Counter(this, name
+ ".counter1", 1);
52 counter
[2] = new Counter(this, name
+ ".counter2", 2);
56 Intel8254Timer::writeControl(const CtrlReg data
)
60 if (sel
== ReadBackCommand
)
61 panic("PITimer Read-Back Command is not implemented.\n");
63 if (data
.rw
== LatchCommand
)
64 counter
[sel
]->latchCount();
66 counter
[sel
]->setRW(data
.rw
);
67 counter
[sel
]->setMode(data
.mode
);
68 counter
[sel
]->setBCD(data
.bcd
);
73 Intel8254Timer::serialize(const string
&base
, ostream
&os
)
75 // serialize the counters
76 counter
[0]->serialize(base
+ ".counter0", os
);
77 counter
[1]->serialize(base
+ ".counter1", os
);
78 counter
[2]->serialize(base
+ ".counter2", os
);
82 Intel8254Timer::unserialize(const string
&base
, Checkpoint
*cp
,
83 const string
§ion
)
85 // unserialze the counters
86 counter
[0]->unserialize(base
+ ".counter0", cp
, section
);
87 counter
[1]->unserialize(base
+ ".counter1", cp
, section
);
88 counter
[2]->unserialize(base
+ ".counter2", cp
, section
);
91 Intel8254Timer::Counter::Counter(Intel8254Timer
*p
,
92 const string
&name
, unsigned int _num
)
93 : _name(name
), num(_num
), event(this), initial_count(0),
94 latched_count(0), period(0), mode(0), output_high(false),
95 latch_on(false), read_byte(LSB
), write_byte(LSB
), parent(p
)
101 Intel8254Timer::Counter::latchCount()
103 // behave like a real latch
107 latched_count
= currentCount();
112 Intel8254Timer::Counter::currentCount()
114 int clocks
= event
.clocksLeft();
116 warn_once("Reading current count from inactive timer.\n");
119 if (mode
== RateGen
|| mode
== SquareWave
)
126 Intel8254Timer::Counter::read()
132 return (uint8_t)latched_count
;
137 return latched_count
>> 8;
140 panic("Shouldn't be here");
143 uint16_t count
= currentCount();
147 return (uint8_t)count
;
154 panic("Shouldn't be here");
160 Intel8254Timer::Counter::write(const uint8_t data
)
162 switch (write_byte
) {
164 initial_count
= (initial_count
& 0xFF00) | data
;
166 if (event
.scheduled())
167 parent
->deschedule(event
);
173 initial_count
= (initial_count
& 0x00FF) | (data
<< 8);
174 // In the RateGen or SquareWave modes, the timer wraps around and
175 // triggers on a value of 1, not 0.
176 if (mode
== RateGen
|| mode
== SquareWave
)
177 period
= initial_count
- 1;
179 period
= initial_count
;
190 Intel8254Timer::Counter::setRW(int rw_val
)
192 if (rw_val
!= TwoPhase
)
193 panic("Only LSB/MSB read/write is implemented.\n");
197 Intel8254Timer::Counter::setMode(int mode_val
)
199 if(mode_val
!= InitTc
&& mode_val
!= RateGen
&&
200 mode_val
!= SquareWave
)
201 panic("PIT mode %#x is not implemented: \n", mode_val
);
207 Intel8254Timer::Counter::setBCD(int bcd_val
)
210 panic("PITimer does not implement BCD counts.\n");
214 Intel8254Timer::Counter::outputHigh()
220 Intel8254Timer::Counter::serialize(const string
&base
, ostream
&os
)
222 paramOut(os
, base
+ ".initial_count", initial_count
);
223 paramOut(os
, base
+ ".latched_count", latched_count
);
224 paramOut(os
, base
+ ".period", period
);
225 paramOut(os
, base
+ ".mode", mode
);
226 paramOut(os
, base
+ ".output_high", output_high
);
227 paramOut(os
, base
+ ".latch_on", latch_on
);
228 paramOut(os
, base
+ ".read_byte", read_byte
);
229 paramOut(os
, base
+ ".write_byte", write_byte
);
232 if (event
.scheduled())
233 event_tick
= event
.when();
234 paramOut(os
, base
+ ".event_tick", event_tick
);
238 Intel8254Timer::Counter::unserialize(const string
&base
, Checkpoint
*cp
,
239 const string
§ion
)
241 paramIn(cp
, section
, base
+ ".initial_count", initial_count
);
242 paramIn(cp
, section
, base
+ ".latched_count", latched_count
);
243 paramIn(cp
, section
, base
+ ".period", period
);
244 paramIn(cp
, section
, base
+ ".mode", mode
);
245 paramIn(cp
, section
, base
+ ".output_high", output_high
);
246 paramIn(cp
, section
, base
+ ".latch_on", latch_on
);
247 paramIn(cp
, section
, base
+ ".read_byte", read_byte
);
248 paramIn(cp
, section
, base
+ ".write_byte", write_byte
);
251 paramIn(cp
, section
, base
+ ".event_tick", event_tick
);
253 parent
->schedule(event
, event_tick
);
256 Intel8254Timer::Counter::CounterEvent::CounterEvent(Counter
* c_ptr
)
258 interval
= (Tick
)(Clock::Float::s
/ 1193180.0);
263 Intel8254Timer::Counter::CounterEvent::process()
265 switch (counter
->mode
) {
267 counter
->output_high
= true;
271 setTo(counter
->period
);
274 panic("Unimplemented PITimer mode.\n");
276 counter
->parent
->counterInterrupt(counter
->num
);
280 Intel8254Timer::Counter::CounterEvent::setTo(int clocks
)
283 panic("Timer can't be set to go off instantly.\n");
284 DPRINTF(Intel8254Timer
, "Timer set to curTick + %d\n",
286 counter
->parent
->schedule(this, curTick
+ clocks
* interval
);
290 Intel8254Timer::Counter::CounterEvent::clocksLeft()
294 return (when() - curTick
+ interval
- 1) / interval
;
298 Intel8254Timer::Counter::CounterEvent::description() const
300 return "Intel 8254 Interval timer";