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31 lines
920 B
ArmAsm
31 lines
920 B
ArmAsm
.export psg_init
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.include "pce.inc"
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.segment "ONCE"
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psg_init:
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clx
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stz PSG_GLOBAL_PAN ; Silence global balance
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psg_clear_loop:
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stx PSG_CHAN_SELECT ; Select channel
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stz PSG_FREQ_LO ; Clear frequency LSB
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stz PSG_FREQ_HI ; Clear frequency MSB
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stz PSG_CHAN_CTRL ; Clear volume
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stz PSG_CHAN_PAN ; Clear balance
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stz PSG_NOISE ; Clear noise control
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stz PSG_LFO_FREQ ; Clear LFO frequency
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stz PSG_LFO_CTRL ; Clear LFO control
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cly
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psg_clear_waveform:
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stz PSG_CHAN_DATA ; Clear waveform byte
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iny
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cpy #$20
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bne psg_clear_waveform
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inx
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cpx #$06
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bne psg_clear_loop
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rts
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