Patent US 3,969,724

A central processing unit (CPU) is disclosed which can be used in a microprocessor and which has a relatively simple architecture enabling it to perform rapid data processing operations. The CPU has a plurality of registers, an arithmetic logic unit (ALU), and a multiplexor which selects one of the ALU operands. A relatively large scratchpad is included in the CPU to eliminate time-consuming addressing of memories outside the CPU. A parallel architecture and the ability to perform simultaneous operations also enhance the CPU speed. The CPU control unit has a read only memory (ROM) for storage of micro control instructions and a program counter capable of addressing the ROM either sequentially or in accordance with a specific address for execution of jump instructions.