The 16-bit Zilog Z8001 has the following general instruction format:

The mode field specifies how to locate the operands from the operand fields. The w/b field is used in certain instructions to specify whether the operands are bytes or 16-bit words. The operand 1 field may (depending on the mode field contents) specify one of 16 general-purpose registers. The operand 2 field may specify any general-purpose registers except register 0.When the operand 2 field is all zeros, each of the original opcodes takes on a new meaning.
a. How many opcodes are provided on the Z8001?
b. Suggest an efficient way to provide more opcodes and indicate the trade-off involved.

Transcribed Image Text:

15 14 1312 11 10 9 8 7 6 5 43 21 0 Mode Operand 2 Operand 1