Commodore Amiga - The Copper and the 68000; Summary of Copper Instructions

When the BFD bit is a 0, the logic of the Copper WAIT instruction is modified. The
Copper will WAIT until the beam counter comparison is true
and the blitter has
finished.
The blitter has finished when the blitter-finished flag is set. This bit should be
unset with caution. It could possibly prevent some screen displays or prevent objects
from being displayed correctly.
For more information about using the blitter,
see chapter 6, "Blitter Hardware."
THE COPPER AND THE 68000
On those occasions when the Copper's instructions do not suffice, you can interrupt the
68000 and use its instruction set instead. The 68000 can poll for interrupt flags set in
the INTREQ register by various devices. To interrupt the 68000, use the Copper MOVE
instruction
to store a 1 into the following bits of INTREQ:
Table
2-1: Interrupting the 68000
Bit Number Name Function
15 SET /CLR Set/Clear control bit. Determines
if bits written with a 1 get set
or cleared.
4
COPEN Coprocessor interrupting 68000.
See chapter 7, "System Control Hardware," for more information about interrupts.
Summary of Copper Instructions
The table below shows a summary of the bit positions for each of the Copper instruc-
tions. See appendix A for a summary of all registers.
24 Coprocessor Hardware