COPPER INTERRUPT
Bit 4, COPER, is used by the Copper to issue a level 3 interrupt. The Copper can change
the content of any of the bits of this register, as it can write any value into most of the
machine registers. However, this bit has been reserved for specifically identifying the
Copper as the interrupt source.
Generally, you use this bit when you want to sense that the display beam has reached a
specific position on the screen, and you wish to change
something in memory based on this occurrence.
AUDIO INTERRUPTS
Bits 10 - 7, AUD3 - 0, are assigned to the audio channels. They are called AUD3, AUD2,
AUDl, and AUD0 and are assigned to channels 3, 2,1, and 0, respectively.
This level 4 interrupt signals "audio block done". When the audio DMA is operating in
automatic mode, this interrupt occurs when the last word in an audio data stream has
been accessed. In manual mode, it occurs when the audio data register is ready to accept
another word of data.
See Chapter 5, "Audio Hardware," for more information about interrupt generation and
timing.
BLITTER INTERRUPT
Bit 6, BLIT, signals "blitter finished." If this bit is a 1, it indicates that the blitter has
completed the requested data transfer. The blitter is now ready to accept another task.
This bit generates a level 3 interrupt.
DISK INTERRUPT
Bits 12 and 1 of the interrupt registers are assigned to disk interrupts.
Bit 12, DSKSYN, indicates that the sync register matches disk data. This bit generates a
level 5 interrupt.
- System Control Hardware 215 -
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