Initial PSG support. Mostly works, noise channel is borked though.

1 files changed, 32 insertions, 0 deletions

diff --git a/psg.h b/psg.h
new file mode 100644
index 0000000..7d36f5c
--- /dev/null
+++ b/psg.h
@@ -0,0 +1,32 @@
+#ifndef PSG_CONTEXT_H_
+#define PSG_CONTEXT_H_
+
+#include <stdint.h>
+
+typedef struct {
+	int16_t  *audio_buffer;
+	int16_t  *back_buffer;
+	double   buffer_fraction;
+	double   buffer_inc;
+	uint32_t buffer_pos;
+	uint32_t back_pos;
+	uint32_t cycles;
+	uint32_t samples_frame;
+	uint16_t lsfr;
+	uint16_t counter_load[4];
+	uint16_t counters[4];
+	uint8_t  volume[4];
+	uint8_t  output_state[4];
+	uint8_t  noise_out;
+	uint8_t  noise_use_tone;
+	uint8_t  noise_type;
+	uint8_t  latch;
+} psg_context;
+
+
+void psg_init(psg_context * context, uint32_t sample_rate, uint32_t clock_rate, uint32_t samples_frame);
+void psg_write(psg_context * context, uint8_t value);
+void psg_run(psg_context * context, uint32_t cycles);
+
+#endif //PSG_CONTEXT_H_
+