Patent · US Expired

One-chip microcomputer system having function for substantially correcting contents of program

US5574926A · kind A · utility

20Cited by
11References
8Claims
0Family size

Assignee

Inventors

Key dates

Filing dateMar 11, 1994
Grant dateNov 12, 1996
Priority date
Expiry dateMar 11, 2014

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG06F15/7814
  • WIPO fieldComputer technology
  • WIPO sectorElectrical engineering

Abstract

A one-chip microcomputer system includes a one-chip microcomputer, a nonvolatile memory which can electrically rewritably store changing data of a program stored in a mask ROM of the one-chip microcomputer, an input unit (connection unit) for receiving data to be written in the nonvolatile memory from an external device, and an object to be controlled by the one-chip microcomputer. In one aspect, the nonvolatile memory has first and second correction data areas, and first and second memories for respectively designating these areas. Upon reception of an initialization signal from the external device connected to the input unit, only the second memory for designating the second correction data area is initialized. In another aspect, the mask ROM stores ROM version data, and the nonvolatile memory stores board version data. Upon writing of the data via the input unit, bug correction data is selected based on the ROM version data and the board version data, and the selected data is written in the nonvolatile memory. In still another aspect, the nonvolatile memory has a first area for storing data for correcting a bug in the program, a second area for storing data for changing a specif…

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