Chip topography for MOS integrated circuitry microprocessor chip

摘要

The chip topography of an MOS microprocessor chip. The chip architecture includes an internal data bus and an internal address bus. Input/output circuitry is located along the top edge of the chip and is coupled to the data bus. Output circuitry is located along the bottom edge and coupled to the address bus. A program storage area which includes a ROM is located in the lower left hand corner of the chip. The ROM contains instruction words for defining the operation of the microprocessor. A data storage area which includes a RAM is located in the upper left hand corner of the chip and is coupled to the data bus. An ALU area is located to the right of the data storage area and is coupled to the data bus for performing arithmetic and logic operations on data. A condition decode ROM located in the approximate center of the chip is coupled to the data bus and is used for decoding a condition field of an instruction word received from the ROM. A bus control area is located in the upper right hand corner of the chip. A programmed control area is located between the ALU area and the bus control area in the upper right hand portion of the chip and is coupled to the data bus for receiving instruction words from the program storage area and for generating commands which define the operation of the microprocessor in response to the instruction words. A clock/T-counter is located in the lower right hand corner and is used for synchronizing data signal flow in the micrprocessor. A stack area is located in the lower right hand portion of the chip. Within this stack area are various registers located from top to bottom as follows; write X circuitry, an X register a stack array, stack read/write circuitry, a memory address register, and an incrementer. A stack control is located between the aforementioned stack circuitry and the right hand edge. In addition, a RAM decode is located between the RAM and the left hand edge, a ROM column decode is located between the ROM and the bottom edge, and a ROM row decode is located between the ROM and the stack area.