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1-bit Microprocessor: Overview Details Name: icu Created: 15-Oct-2006 23:04:38 Updated: 17-Oct-2006 18:47:29 CVS: no files in cvs Other project properties Category :: Microprocessor Language :: VHDL License :: GPL Phaze :: Design done Development status :: Alpha Project maintainers Ken Boyette Statistics view ICU - 1-bit Microprocessor This project, written in VHDL, implements a microprocessor based on the Motorola MC14500B Industrial Control Unit (ICU). In addition to the basic emulation of the microprocessor, a 12-bit program counter and jump/branch logic have been added. There are also input and output registers to provide a complete microcontroller, suitable for a variety of real-world control applications. From an educational perspective the ICU project should provide a useful insight into basic microprocessor operation as well as a practical introduction to circuit design using VHDL. While a "1-bit" microprocessor might seem almost useless in light of modern 8/16/32 and 64-bit architectures, the ICU is really quite capable of implementing logic control functions. The original MC14500B was designed to replace hard logic with a simple programmable sequencer targeting "ladder logic" applications where output decisions were based on simple boolean logic applied to the input. In addition to the VHDL implementation, the project will provide an open source "assembly language" compiler written in C. The assembler will output straight binary and "S-record" formatted binary for prom programming. Features Motorola MC14500B emulation 4-bit Instruction Unit 1-bit data bus Program Counter Unit 12-bit program counter Loadable for Jump and Branch Instructions Input Register 16 addressable input bits Output Register 16 addressable latched output bits With readback Status Preparing VHDL source for OpenCores Planning details for the "Assembly Language Compiler"