[256] | 1 | ; Project name : Assembly Library |
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[589] | 2 | ; Description : System Timer (8254) related equates and macros. |
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[256] | 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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[589] | 36 | ; Timer 2 is connected to PC Speaker that can be controlled from port 61h. |
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[256] | 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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