Patent · US Expired

Microcode control mechanism utilizing programmable microcode repeat counter

US4556938A · kind A · utility

39Cited by
8References
13Claims
0Family size

Assignee

Inventors

Key dates

Filing dateFeb 22, 1982
Grant dateDec 3, 1985
Priority date
Expiry dateFeb 22, 2002

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG06F9/264
  • WIPO fieldComputer technology
  • WIPO sectorElectrical engineering

Abstract

A microcode control mechanism is provided for producing the sequences of microwords used to control the execution of processor instructions in a microprogrammed data processor. This microcode control mechanism includes sequence counter circuitry for supplying a sequence of numbers and a programmable logic array mechanism responsive to the processor instruction and to the sequence of numbers for producing a sequence of microwords needed to execute the instruction. The microcode control mechanism also includes repeat circuitry responsive to a predetermined microword produced by the programmable logic array mechanism for setting the sequence counter circuitry back to a count which is less than the current count for causing a selected portion of the microword sequence to be repeated. The microcode control mechanism further includes a programmable repeat counter for counting the number of times the selected portion is repeated and for disabling the repeating action after a selected number of repeats.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.