Patent · US Expired

Method of testing n-bit programmable counters

US4991185A · kind A · utility

2Cited by
3References
16Claims
0Family size

Assignee

Inventors

Key dates

Filing dateJan 3, 1990
Grant dateFeb 5, 1991
Priority date
Expiry dateJan 3, 2010

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG06F2201/88
  • WIPO fieldMeasurement
  • WIPO sectorInstruments

Abstract

This invention relates to a method of testing an n-bit programmable counter. It is desired to test the n-bit programmable counter in fewer than 2.sup.n cycles. Accordingly, a counter value output on the counter is coupled to a variable increment rate input on the counter. Each bit of the counter is reset to a binary 0 initial state. A binary 1 state is loaded into a carry-in bit of the counter and the counter is iteratively doubled, by means of the coupling between the counter value output and the variable increment rate input, until a carry-out bit of the counter assumes the binary 1 state to thereby allow the counter to be fully tested in n+1 iterations. The counter value output and the variable increment rate input are decoupled from the counter when the counter is not being tested. The counter is provided with a parallel load input to allow simultaneous resetting of each bit. Intermediate counter values may be checked to provide a means for localizing errors within the counter.

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