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 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. 15 * 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 26 * DAMAGES. 27 * 28 * Authors: Ali G. Saidi 29 * Andrew L. Schultz 30 * Miguel J. Serrano 31 */ 32 33#ifndef __DEV_8254_HH__ 34#define __DEV_8254_HH__ 35 36#include <string> 37#include <iostream> 38 39#include "base/bitunion.hh" 40#include "sim/eventq.hh" 41#include "sim/host.hh" 42#include "sim/serialize.hh" 43 44/** Programmable Interval Timer (Intel 8254) */ 45class Intel8254Timer : public EventManager 46{
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47 protected: |
48 BitUnion8(CtrlReg) 49 Bitfield<7, 6> sel; 50 Bitfield<5, 4> rw; 51 Bitfield<3, 1> mode; 52 Bitfield<0> bcd; 53 EndBitUnion(CtrlReg) 54 55 enum SelectVal { 56 SelectCounter0, 57 SelectCounter1, 58 SelectCounter2, 59 ReadBackCommand 60 }; 61 62 enum ReadWriteVal { 63 LatchCommand, 64 LsbOnly, 65 MsbOnly, 66 TwoPhase 67 }; 68 69 enum ModeVal { 70 InitTc, 71 OneShot, 72 RateGen, 73 SquareWave, 74 SoftwareStrobe, 75 HardwareStrobe 76 }; 77 78 /** Counter element for PIT */ 79 class Counter 80 { 81 /** Event for counter interrupt */ 82 class CounterEvent : public Event 83 { 84 private: 85 /** Pointer back to Counter */ 86 Counter* counter; 87 Tick interval; 88 89 public: 90 CounterEvent(Counter*); 91 92 /** Event process */ 93 virtual void process(); 94 95 /** Event description */ 96 virtual const char *description() const; 97 98 friend class Counter; 99 100 void setTo(int clocks); 101 }; 102 103 private: 104 std::string _name; 105 const std::string &name() const { return _name; } 106 107 CounterEvent event; 108 109 /** Current count value */ 110 uint16_t count; 111 112 /** Latched count */ 113 uint16_t latched_count; 114 115 /** Interrupt period */ 116 uint16_t period; 117 118 /** Current mode of operation */ 119 uint8_t mode; 120 121 /** Output goes high when the counter reaches zero */ 122 bool output_high; 123 124 /** State of the count latch */ 125 bool latch_on; 126 127 /** Set of values for read_byte and write_byte */ 128 enum {LSB, MSB}; 129 130 /** Determine which byte of a 16-bit count value to read/write */ 131 uint8_t read_byte, write_byte; 132 133 /** Pointer to container */ 134 Intel8254Timer *parent; 135 136 public: 137 Counter(Intel8254Timer *p, const std::string &name); 138 139 /** Latch the current count (if one is not already latched) */ 140 void latchCount(); 141 142 /** Set the read/write mode */ 143 void setRW(int rw_val); 144 145 /** Set operational mode */ 146 void setMode(int mode_val); 147 148 /** Set count encoding */ 149 void setBCD(int bcd_val); 150 151 /** Read a count byte */ 152 uint8_t read(); 153 154 /** Write a count byte */ 155 void write(const uint8_t data); 156 157 /** Is the output high? */ 158 bool outputHigh(); 159 160 /** 161 * Serialize this object to the given output stream. 162 * @param base The base name of the counter object. 163 * @param os The stream to serialize to. 164 */ 165 void serialize(const std::string &base, std::ostream &os); 166 167 /** 168 * Reconstruct the state of this object from a checkpoint. 169 * @param base The base name of the counter object. 170 * @param cp The checkpoint use. 171 * @param section The section name of this object 172 */ 173 void unserialize(const std::string &base, Checkpoint *cp, 174 const std::string §ion); 175 }; 176
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176 private:
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177 protected: |
178 std::string _name; 179 const std::string &name() const { return _name; } 180 181 /** PIT has three seperate counters */ 182 Counter *counter[3]; 183 184 public:
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184 /** Public way to access individual counters (avoid array accesses) */
185 Counter counter0;
186 Counter counter1;
187 Counter counter2;
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185
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186 Intel8254Timer(EventManager *em, const std::string &name, 187 Counter *counter0, Counter *counter1, Counter *counter2); 188 |
189 Intel8254Timer(EventManager *em, const std::string &name); 190 191 /** Write control word */ 192 void writeControl(const CtrlReg data); 193
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194 uint8_t 195 readCounter(unsigned int num) 196 { 197 assert(num < 3); 198 return counter[num]->read(); 199 } 200 201 void 202 writeCounter(unsigned int num, const uint8_t data) 203 { 204 assert(num < 3); 205 counter[num]->write(data); 206 } 207 208 bool 209 outputHigh(unsigned int num) 210 { 211 assert(num < 3); 212 return counter[num]->outputHigh(); 213 } 214 |
215 /** 216 * Serialize this object to the given output stream. 217 * @param base The base name of the counter object. 218 * @param os The stream to serialize to. 219 */ 220 void serialize(const std::string &base, std::ostream &os); 221 222 /** 223 * Reconstruct the state of this object from a checkpoint. 224 * @param base The base name of the counter object. 225 * @param cp The checkpoint use. 226 * @param section The section name of this object 227 */ 228 void unserialize(const std::string &base, Checkpoint *cp, 229 const std::string §ion); 230}; 231 232#endif // __DEV_8254_HH__
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