Underwater Depths

Track 40

Composed by Akira Fujiwara, Minako Hamano

GBA

Channel Breakdown

6 channels

ARM7TDMI (software mixing)GSF format

Pulse 1pulse

Legacy Game Boy pulse channel with sweep

Pulse 2pulse

Legacy Game Boy pulse channel

Wavewave

Legacy Game Boy programmable wave channel

Noisenoise

Legacy Game Boy noise channel

Direct Sound Asample

8-bit PCM DMA channel driven by software mixing

Direct Sound Bsample

8-bit PCM DMA channel driven by software mixing

pulse (2)

wave (1)

noise (1)

sample (2)

The GBA inherits the Game Boy's 4 hardware channels and adds 2 Direct Sound DMA channels for PCM sample playback. Most games use software mixing on the ARM7 CPU to play many more simultaneous instrument samples through the 2 DMA channels.