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Data Organization

The basic unit of data manipulated by the WC34000 is a 16 bit word. The machine's memory is word-addressable (rather than byte-addressable as in the 68000). Up to 65,536 words of memory may be addressed.

The processor includes eight 16 bit data registers and eight 16 bit address registers. The data registers are referred to as D0, D1, ... D7. The address registers are referred to as A0, A1, ... A7. Several instructions reference A7 implicitly as a stack pointer. Accordingly, it can also be referenced by the name SP.

In addition, the processor includes a program counter register (PC) and a condition code register (CCR). The CCR in the WC34000 contains three bits named N (negative), Z (zero) and V (overflow). These bits are changed only by the CMP (compare) instuction. They are tested by the conditional branch instructions.



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