Differences
This shows you the differences between two versions of the page.
| Both sides previous revisionPrevious revisionNext revision | Previous revision | ||
| spu [2024/07/01 11:27] – ↷ Page name changed from sound to spu admin | spu [2025/02/08 17:48] (current) – [Beat interrupts] simer | ||
|---|---|---|---|
| Line 97: | Line 97: | ||
| + | ====== Beat interrupts ====== | ||
| + | The SPU provides a beat interrupt which can be used to drive sequenced music tracks. | ||
| + | |||
| + | Beat interrupts are enabled by writing to the enable bit (bit 15) of the beat count register (0x3405). | ||
| + | |||
| + | When enabled, the beat count will decrease at a regular rate governed by the beat base count register. When the beat count reaches zero, the beat interrupt will trigger IRQ4 in the CPU. The interrupt is acknowledged by writing 1 to the status bit (bit 14). The beat count is not automatically reset, instead the program should fill the beat count field with a new value. | ||
| + | |||
| + | The beat base count register (0x3404) defines the rate in which the beat count is automatically decreased as '' | ||
