diff options
| -rw-r--r-- | ym2612.c | 41 | ||||
| -rw-r--r-- | ym2612.h | 5 |
2 files changed, 30 insertions, 16 deletions
@@ -58,6 +58,9 @@ enum { #define BIT_TIMERA_RESET 0x10 #define BIT_TIMERB_RESET 0x20 +#define BIT_TIMERA_LOAD 0x40 +#define BIT_TIMERB_LOAD 0x80 + #define BIT_STATUS_TIMERA 0x1 #define BIT_STATUS_TIMERB 0x2 @@ -241,7 +244,7 @@ void ym_init(ym2612_context * context, uint32_t sample_rate, uint32_t master_clo #define YM_MOD_SHIFT 1 #define TIMER_A_MAX 1023 -#define TIMER_B_MAX (255*16) +#define TIMER_B_MAX 255 void ym_run(ym2612_context * context, uint32_t to_cycle) { @@ -254,22 +257,29 @@ void ym_run(ym2612_context * context, uint32_t to_cycle) if (context->timer_a != TIMER_A_MAX) { context->timer_a++; } else { - if (context->timer_control & BIT_TIMERA_OVEREN) { + if (context->timer_control & BIT_TIMERA_LOAD) { + context->timer_control &= ~BIT_TIMERA_LOAD; + } else if (context->timer_control & BIT_TIMERA_OVEREN) { context->status |= BIT_STATUS_TIMERA; } context->timer_a = context->timer_a_load; } } - if (context->timer_control & BIT_TIMERB_ENABLE) { - if (context->timer_b != TIMER_B_MAX) { - context->timer_b++; - } else { - if (context->timer_control & BIT_TIMERB_OVEREN) { - context->status |= BIT_STATUS_TIMERB; + if (!context->sub_timer_b) { + if (context->timer_control & BIT_TIMERB_ENABLE) { + if (context->timer_b != TIMER_B_MAX) { + context->timer_b++; + } else { + if (context->timer_control & BIT_TIMERB_LOAD) { + context->timer_control &= ~BIT_TIMERB_LOAD; + } else if (context->timer_control & BIT_TIMERB_OVEREN) { + context->status |= BIT_STATUS_TIMERB; + } + context->timer_b = context->timer_b_load; } - context->timer_b = context->timer_b_load; } } + context->sub_timer_b += 0x10; //Update LFO if (context->lfo_enable) { if (context->lfo_counter) { @@ -672,16 +682,19 @@ void ym_data_write(ym2612_context * context, uint8_t value) context->timer_a_load |= value & 0x3; break; case REG_TIMERB: - context->timer_b_load = value * 16; + context->timer_b_load = value; break; case REG_TIME_CTRL: { if (value & BIT_TIMERA_ENABLE && !(context->timer_control & BIT_TIMERA_ENABLE)) { - context->timer_a = context->timer_a_load; + context->timer_a = TIMER_A_MAX; + context->timer_control |= BIT_TIMERA_LOAD; } if (value & BIT_TIMERB_ENABLE && !(context->timer_control & BIT_TIMERB_ENABLE)) { - context->timer_b = context->timer_b_load; + context->timer_b = TIMER_B_MAX; + context->timer_control |= BIT_TIMERB_LOAD; } - context->timer_control = value & 0xF; + context->timer_control &= (BIT_TIMERA_LOAD | BIT_TIMERB_LOAD); + context->timer_control |= value & 0xF; if (value & BIT_TIMERA_RESET) { context->status &= ~BIT_STATUS_TIMERA; } @@ -837,7 +850,7 @@ void ym_print_channel_info(ym2612_context *context, int channel) "Feedback: %d\n" "Pan: %s\n" "AMS: %d\n" - "PMS: %d\n", + "PMS: %d\n", channel+1, chan->algorithm, chan->feedback, chan->lr == 0xC0 ? "LR" : chan->lr == 0x80 ? "L" : chan->lr == 0x40 ? "R" : "", chan->ams, chan->pms); @@ -75,10 +75,11 @@ typedef struct { ym_channel channels[NUM_CHANNELS]; uint16_t timer_a; uint16_t timer_a_load; - uint16_t timer_b; - uint16_t timer_b_load; uint16_t env_counter; ym_supp ch3_supp[3]; + uint8_t timer_b; + uint8_t sub_timer_b; + uint8_t timer_b_load; uint8_t ch3_mode; uint8_t current_op; uint8_t current_env_op; |