Patent · US Expired

Microcontroller with a reconfigurable program status word

US5664156A · kind A · utility

6Cited by
10References
7Claims
0Family size

Assignee

Inventors

Key dates

Filing dateSep 16, 1994
Grant dateSep 2, 1997
Priority date
Expiry dateSep 16, 2014

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG06F9/30094
  • WIPO fieldComputer technology
  • WIPO sectorElectrical engineering

Abstract

A microcontroller routs bits of a PSW to and from a bus depending on a mode. Whenever in a mode compatible with a prior generation microcontroller, address and routing circuitry using decoders and multiplexers, during a read operation, places bits of the PSW of the current generation on the bus at a location of the prior generation microcontroller. In a write operator circuitry also moves bits from the bus in an arrangement compatible with the prior generation and stores them in the arrangement of the current generation. The circuitry also allows various units such as the ALU to update the PSW register bits directly without making a bus transfer.

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