Patent · US Expired

Floating point processor with internal free-running clock

US5153848A · kind A · utility

33Cited by
9References
25Claims
0Family size

Assignee

Inventors

Key dates

Filing dateOct 12, 1990
Grant dateOct 6, 1992
Priority date
Expiry dateOct 12, 2010

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG06F2207/5442
  • WIPO fieldComputer technology
  • WIPO sectorElectrical engineering

Abstract

In a high-speed binary multiplier circuit, the multiplicand is segmented into a series of 8-bit slices and the multiplier is modified-Booth recorded into 3-bit groups. The corresponding partial product terms are reduced in a regular array of small carry-save adder (CSA) cells. Iterative use of the CSA array provides the Wallace tree function in one-seventh the chip area or number of adders of a conventional implementation. The multiplier and divider are pipelined internally, driven by a fast, two-phase internal clock that is transparent to the user. The internal clock stops and restarts upon loading new operand and instruction data to synchronize the internal clock to the system clock. Other aspects of the invention include two-speed internal clocking for operation and testing, two-node clock stopping and distributed buffering of system clock signals.

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