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 -