1 | ; Project name : Assembly Library |
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2 | ; Description : System Timer (8254) relates equates and macros. |
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3 | %ifndef SYSTEMTIMER_INC |
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4 | %define SYSTEMTIMER_INC |
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5 | |
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6 | ; Timer/Counter to program |
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7 | TIMER_0 EQU (0<<6) |
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8 | TIMER_1 EQU (1<<6) |
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9 | TIMER_2 EQU (2<<6) |
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10 | |
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11 | ; Counter commands |
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12 | LATCH EQU (0<<4) ; Counter Latch Command (latches the count for reading) |
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13 | READ_OR_WRITE_LSB_ONLY EQU (1<<4) ; MSB is always zero |
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14 | READ_OR_WRITE_MSB_ONLY EQU (2<<4) ; LSB is always zero |
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15 | READ_OR_WRITE_LSB_THEN_MSB EQU (3<<4) |
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16 | |
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17 | ; Timer modes |
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18 | MODE_0_SINGLE_TIMEOUT EQU (0<<1) ; Interrupt on Terminal Count |
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19 | MODE_1_ONE_SHOT EQU (1<<1) ; Hardware Retriggerable One-Shot |
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20 | MODE_2_RATE_GENERATOR EQU (2<<1) |
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21 | MODE_3_SQUARE_WAVE_MODE EQU (3<<1) |
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22 | MODE_4_SOFTWARE_TRIGGERED_STROBE EQU (4<<1) |
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23 | MODE_5_HARDWARE_RETRIGGERABLE_STROBE EQU (5<<1) |
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24 | |
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25 | ; Binary / BCD Mode |
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26 | BINARY_COUNTER EQU 0 |
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27 | BCD_COUNTER EQU 1 |
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28 | |
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29 | |
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30 | ; Ports |
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31 | COUNT_REGISTER_0 EQU 40h ; Timer 0 Count Register (System Timer Ticks) |
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32 | COUNT_REGISTER_1 EQU 41h ; Timer 1 Count Register (DRAM Refresh) |
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33 | COUNT_REGISTER_2 EQU 42h ; Timer 2 Count Register (General Use) |
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34 | CONTROL_WORD_REGISTER_out EQU 43h |
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35 | |
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36 | ; Timer 2 is Connected to PC Speaker that can be controller from port 61h. |
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37 | SPEAKER_CONTROL_REGISTER EQU 61h |
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38 | FLG_TIMER_2_OUTPUT_in EQU (1<<5) ; AT+ only |
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39 | FLG_SPEAKER_DATA_ENABLED EQU (1<<1) |
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40 | FLG_SPEAKER_GATE_TIMER_2_ON EQU (1<<0) |
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41 | |
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42 | |
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43 | ; The duration of one tick |
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44 | TIMER_CYCLE_TIME EQU 838 ; nanosecs |
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45 | |
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46 | |
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47 | |
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48 | |
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49 | ;-------------------------------------------------------------------- |
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50 | ; OUTPUT_COUNTER_COMMAND_TO |
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51 | ; Parameters: |
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52 | ; %1: TIMER_0, TIMER_1 or TIMER_2 |
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53 | ; %2: Command to counter |
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54 | ; %3: Timer mode |
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55 | ; %4: BINARY_COUNTER or BCD_COUNTER |
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56 | ; Returns: |
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57 | ; Nothing |
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58 | ; Corrupts registers: |
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59 | ; AL |
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60 | ;-------------------------------------------------------------------- |
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61 | %macro OUTPUT_COUNTER_COMMAND_TO 4 |
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62 | mov al, %1 | %2 | %3 | %4 |
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63 | out CONTROL_WORD_REGISTER_out, al |
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64 | %endmacro |
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65 | |
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66 | |
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67 | ;-------------------------------------------------------------------- |
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68 | ; WRITE_COUNT_FROM_AL_TO |
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69 | ; WRITE_COUNT_FROM_AX_TO |
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70 | ; Parameters: |
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71 | ; %1: TIMER_0, TIMER_1 or TIMER_2 |
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72 | ; AX: Count to write to timer |
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73 | ; Returns: |
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74 | ; Nothing |
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75 | ; Corrupts registers: |
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76 | ; AL (WRITE_COUNT_FROM_AX_TO only) |
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77 | ;-------------------------------------------------------------------- |
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78 | %macro WRITE_COUNT_FROM_AL_TO 1 |
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79 | %ifidni %1, TIMER_0 |
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80 | out COUNT_REGISTER_0, al |
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81 | %elifidni %1, TIMER_1 |
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82 | out COUNT_REGISTER_1, al |
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83 | %elifidni %1, TIMER_2 |
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84 | out COUNT_REGISTER_2, al |
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85 | %else |
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86 | %error "Invalid timer name passed to WRITE_COUNT_FROM_AL_TO" |
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87 | %endif |
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88 | %endmacro |
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89 | |
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90 | %macro WRITE_COUNT_FROM_AX_TO 1 |
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91 | %ifidni %1, TIMER_0 |
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92 | out COUNT_REGISTER_0, al |
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93 | mov al, ah |
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94 | out COUNT_REGISTER_0, al |
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95 | %elifidni %1, TIMER_1 |
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96 | out COUNT_REGISTER_1, al |
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97 | mov al, ah |
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98 | out COUNT_REGISTER_1, al |
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99 | %elifidni %1, TIMER_2 |
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100 | out COUNT_REGISTER_2, al |
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101 | mov al, ah |
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102 | out COUNT_REGISTER_2, al |
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103 | %else |
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104 | %error "Invalid timer name passed to WRITE_COUNT_FROM_AX_TO" |
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105 | %endif |
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106 | %endmacro |
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107 | |
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108 | |
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109 | ;-------------------------------------------------------------------- |
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110 | ; READ_COUNT_TO_AL_FROM |
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111 | ; READ_COUNT_TO_AX_FROM |
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112 | ; Parameters: |
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113 | ; %1: TIMER_0, TIMER_1 or TIMER_2 |
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114 | ; Returns: |
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115 | ; AL/AX: Counter value |
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116 | ; Corrupts registers: |
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117 | ; Nothing |
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118 | ;-------------------------------------------------------------------- |
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119 | %macro READ_COUNT_TO_AL_FROM 1 |
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120 | %ifidni %1, TIMER_0 |
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121 | in al, COUNT_REGISTER_0 |
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122 | %elifidni %1, TIMER_1 |
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123 | in al, COUNT_REGISTER_1 |
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124 | %elifidni %1, TIMER_2 |
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125 | in al, COUNT_REGISTER_2 |
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126 | %else |
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127 | %error "Invalid timer name passed to READ_COUNT_TO_AL_FROM" |
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128 | %endif |
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129 | %endmacro |
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130 | |
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131 | %macro READ_COUNT_TO_AX_FROM 1 |
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132 | %ifidni %1, TIMER_0 |
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133 | in al, COUNT_REGISTER_0 |
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134 | mov ah, al |
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135 | in al, COUNT_REGISTER_0 |
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136 | %elifidni %1, TIMER_1 |
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137 | in al, COUNT_REGISTER_1 |
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138 | mov ah, al |
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139 | in al, COUNT_REGISTER_1 |
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140 | %elifidni %1, TIMER_2 |
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141 | in al, COUNT_REGISTER_2 |
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142 | mov ah, al |
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143 | in al, COUNT_REGISTER_2 |
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144 | %else |
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145 | %error "Invalid timer name passed to READ_COUNT_TO_AX_FROM" |
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146 | %endif |
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147 | xchg al, ah |
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148 | %endmacro |
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149 | |
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150 | |
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151 | ;-------------------------------------------------------------------- |
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152 | ; START_PRECISE_EVENT_TIMER |
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153 | ; Parameters: |
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154 | ; Nothing |
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155 | ; Returns: |
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156 | ; Nothing |
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157 | ; Corrupts registers: |
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158 | ; AL |
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159 | ;-------------------------------------------------------------------- |
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160 | %macro START_PRECISE_EVENT_TIMER 0 |
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161 | in al, SPEAKER_CONTROL_REGISTER |
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162 | or al, FLG_SPEAKER_GATE_TIMER_2_ON |
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163 | out SPEAKER_CONTROL_REGISTER, al |
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164 | %endmacro |
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165 | |
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166 | |
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167 | ;-------------------------------------------------------------------- |
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168 | ; STOP_PRECISE_EVENT_TIMER |
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169 | ; Parameters: |
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170 | ; Nothing |
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171 | ; Returns: |
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172 | ; Nothing |
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173 | ; Corrupts registers: |
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174 | ; AL |
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175 | ;-------------------------------------------------------------------- |
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176 | %macro STOP_PRECISE_EVENT_TIMER 0 |
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177 | in al, SPEAKER_CONTROL_REGISTER |
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178 | and al, ~(FLG_SPEAKER_DATA_ENABLED | FLG_SPEAKER_GATE_TIMER_2_ON) |
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179 | out SPEAKER_CONTROL_REGISTER, al |
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180 | %endmacro |
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181 | |
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182 | |
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183 | %endif ; SYSTEMTIMER_INC |
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