All Copper instructions consist of two 16-bit words in sequential memory locations. Each
time the Copper fetches an instruction, it fetches both words. The MOVE and SKIP
instructions require two memory cycles and two instruction words. Because only the odd
memory cycles are requested by the Copper, four memory cycle times are required per
instruction. The WAIT instruction requires three memory cycles and six memory cycle
times; it takes one extra memory cycle to wake up.
Although the Copper can directly affect only machine registers, it can affect the memory
by setting up a blitter operation. More information about how to use the Copper in
controlling the blitter can be found in the sections called "Control Register" and "Using the
Copper with the Blitter."
The WAIT and MOVE instructions are described below. The SKIP instruction is described in
the "Advanced Topics" section.
THE MOVE INSTRUCTION
The MOVE instruction transfers data from RAM to a register destination. The transferred
data is contained in the second word of the MOVE instruction; the first word contains the
address of the destination register. This procedure is shown in detail in the section called
"Summary of Copper Instructions."
FIRST INSTRUCTION WORD (IR1)
Bit 0 Always set to 0.
Bits 8 - 1 Register destination address (DA8-1).
Bits 15 - 9 Not used, but should be set to 0.
SECOND INSTRUCTION WORD (IR2)
Bits 15 - 0 16 bits of data to be transferred (moved) to the register
destination.
- Coprocessor Hardware 15 -
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