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a cycle-accurate simulation of a microprogrammed CPU.
C CMake
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Eckert Simulator

This is a simulator of the simple CPU with a microprogrammed control unit. For now, the best description of this simulator is still on Dr. Eckert's website.

##Installation and Run instructions This is very much a WYSIWYG layout. I've used CMake for the building process, but there's only one C file (with no dependencies!), so you can compile it in one line with any C compiler that supports binary literals (e.g. 0b011010101). NOTE: There was some very strange behavior observed when this code was compiled with the -O3 flag, so I'd suggest staying clear of using any optimization flags.

There are three input files for the program:

  • ram.txt: this is the "program". It is a raw text file where each line is a 12-bit value. Currently, the program supports a max size of 256 lines, but this wouldn't be hard to adjust.

  • addr.txt: This is the mapping between opcodes and ROM addresses. To extend this instruction set, put the address of the entry point for the new instruction.

  • uprog.txt: This gets loaded into memory as the "control matrix". The clock_tick() function pulls a "µ-instruction" from the ROM, an modifies registers according to the bits in the instruction.

##Future Work

I'd really like to build a decent TUI suing curses, but that'll be on the back burner for quite some time.

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