1 files changed, 13 insertions, 1 deletions

diff --git a/src/gba/gba.h b/src/gba/gba.h
index cdb3b31..b02d745 100644
--- a/src/gba/gba.h
+++ b/src/gba/gba.h
@@ -558,7 +558,7 @@ sound_volume(SoundChannel channels, u8 volume) {
 #define SOUND_SWEEP_DIR(N)    ((N) << 0x3)
 #define SOUND_SWEEP_TIME(N)   ((N) << 0x4)
 
-// DMG frequency bits (Square/Wave).
+// DMG frequency bits (Square/Wave/NOISE).
 #define SOUND_FREQ_TIMED (1 << 0xE)
 #define SOUND_FREQ_RESET (1 << 0xF)
 
@@ -585,6 +585,18 @@ typedef u8 WaveBank[32];
 
 #define SOUND_WAVE_RAM ((WaveBank*)(MEM_IO + 0x90))
 
+// DMG noise control bits.
+#define SOUND_NOISE_LENGTH(N)   (((N) & 0x3F) << 0)
+#define SOUND_NOISE_ENV_TIME(N) (((N) & 0x07) << 0x8)
+#define SOUND_NOISE_ENV_DIR(N)  (((N) & 0x01) << 0xB)
+#define SOUND_NOISE_ENV_VOL(N)  (((N) & 0x0F) << 0xC)
+
+// DMG noise freq bits.
+#define SOUND_NOISE_DIV_FREQ(N)      (((N) & 0x07) << 0)
+#define SOUND_NOISE_COUNTER_STAGE(N) (((N) & 0x01) << 0x3)
+#define SOUND_NOISE_PRESTEP_FREQ(N)  (((N) & 0x0F) << 0x4)
+#define SOUND_NOISE_TIMED_MODE(N)    (((N) & 0x01) << 0xe)
+
 typedef enum {
     NOTE_C_2       , NOTE_C_SHARP_2 , NOTE_D_2       , NOTE_D_SHARP_2 ,
     NOTE_E_2       , NOTE_F_2       , NOTE_F_SHARP_2 , NOTE_G_2       ,