LM3000 Instruction Decoder

From BenningtonWiki

The instruction decoder is functionally the same as a de-multiplexer.

The instruction decoder orchestrates the operation of the input and output enable of each chip. It was designed around the microprocessor's unique instruction set, which was itself designed in a logical, 1 bit manner.

There are four instruction types:

• Move to registers
• Move to ALU
• Arithmetic functions: add, subtract, compare
• Branches

The instruction decoder is composed entirely of combinatorial logic which translates the software into hardware instructions.