1/*
2 * Copyright (c) 2004, 2005
3 * The Regents of The University of Michigan
4 * All Rights Reserved
5 *
6 * This code is part of the M5 simulator.
7 *
8 * Permission is granted to use, copy, create derivative works and

--- 76 unchanged lines hidden (view full) ---

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);
89}
90
91Intel8254Timer::Counter::Counter(Intel8254Timer *p,
92 const string &name, unsigned int _num)
93 : _name(name), num(_num), event(this), 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)
96{
97
98}
99
100void
101Intel8254Timer::Counter::latchCount()
102{
103 // behave like a real latch
104 if(!latch_on) {
105 latch_on = true;
106 read_byte = LSB;
107 latched_count = count;
108 }
109}
110
111uint8_t
112Intel8254Timer::Counter::read()
113{
114 if (latch_on) {
115 switch (read_byte) {
116 case LSB:
117 read_byte = MSB;
118 return (uint8_t)latched_count;
119 break;
120 case MSB:
121 read_byte = LSB;
122 latch_on = false;
123 return latched_count >> 8;
124 break;
125 default:
126 panic("Shouldn't be here");
127 }
128 } else {
129 switch (read_byte) {
130 case LSB:
131 read_byte = MSB;
132 return (uint8_t)count;
133 break;
134 case MSB:
135 read_byte = LSB;
136 return count >> 8;

--- 4 unchanged lines hidden (view full) ---

141 }
142}
143
144void
145Intel8254Timer::Counter::write(const uint8_t data)
146{
147 switch (write_byte) {
148 case LSB:
149 count = (count & 0xFF00) | data;
150
151 if (event.scheduled())
152 parent->deschedule(event);
153 output_high = false;
154 write_byte = MSB;
155 break;
156
157 case MSB:
158 count = (count & 0x00FF) | (data << 8);
159 // In the RateGen or SquareWave modes, the timer wraps around and
160 // triggers on a value of 1, not 0.
161 if (mode == RateGen || mode == SquareWave)
162 period = count - 1;
163 else
164 period = count;
165
166 if (period > 0)
167 event.setTo(period);
168
169 write_byte = LSB;
170 break;
171 }
172}

--- 26 unchanged lines hidden (view full) ---

199Intel8254Timer::Counter::outputHigh()
200{
201 return output_high;
202}
203
204void
205Intel8254Timer::Counter::serialize(const string &base, ostream &os)
206{
207 paramOut(os, base + ".count", count);
208 paramOut(os, base + ".latched_count", latched_count);
209 paramOut(os, base + ".period", period);
210 paramOut(os, base + ".mode", mode);
211 paramOut(os, base + ".output_high", output_high);
212 paramOut(os, base + ".latch_on", latch_on);
213 paramOut(os, base + ".read_byte", read_byte);
214 paramOut(os, base + ".write_byte", write_byte);
215
216 Tick event_tick = 0;
217 if (event.scheduled())
218 event_tick = event.when();
219 paramOut(os, base + ".event_tick", event_tick);
220}
221
222void
223Intel8254Timer::Counter::unserialize(const string &base, Checkpoint *cp,
224 const string &section)
225{
226 paramIn(cp, section, base + ".count", count);
227 paramIn(cp, section, base + ".latched_count", latched_count);
228 paramIn(cp, section, base + ".period", period);
229 paramIn(cp, section, base + ".mode", mode);
230 paramIn(cp, section, base + ".output_high", output_high);
231 paramIn(cp, section, base + ".latch_on", latch_on);
232 paramIn(cp, section, base + ".read_byte", read_byte);
233 paramIn(cp, section, base + ".write_byte", write_byte);
234

--- 31 unchanged lines hidden (view full) ---

266{
267 if (clocks == 0)
268 panic("Timer can't be set to go off instantly.\n");
269 DPRINTF(Intel8254Timer, "Timer set to curTick + %d\n",
270 clocks * interval);
271 counter->parent->schedule(this, curTick + clocks * interval);
272}
273
274const char *
275Intel8254Timer::Counter::CounterEvent::description() const
276{
277 return "Intel 8254 Interval timer";
278}