Technical reports
The SKIM microprogrammer’s guide
W. Stoye
October 1983, 33 pages
DOI: 10.48456/tr-40
Abstract
This paper describes the design and implementation of the SKIM micorprocessor. The processor has a 24 bit ALU with 16 general purpose registers. The main unique feature is a large microcode store of up to 64K 40 bit words, with the intention that the microcode could be used like the machine code on a conventional processor, with operating system primitives being programmed in microcode.
The processor has been constructed from TTL logic, with a microcode assembler running on Phoenix. A debugger for both the hardware and microcode programs runs on the host machine, currently a BBC Microcomputer.
The processor architecture is discussed, with examples of microcode programming. comparisons with other processors are made, and some of the limitations of the present design are noted.
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BibTeX record
@TechReport{UCAM-CL-TR-40, author = {Stoye, W.}, title = {{The SKIM microprogrammer's guide}}, year = 1983, month = oct, url = {https://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-40.pdf}, institution = {University of Cambridge, Computer Laboratory}, doi = {10.48456/tr-40}, number = {UCAM-CL-TR-40} }