Patent · US Expired

Instruction prefetch buffer control

US4714994A · kind A · utility

119Cited by
7References
8Claims
0Family size

Assignee

Inventors

Key dates

Filing dateApr 30, 1985
Grant dateDec 22, 1987
Priority date
Expiry dateApr 30, 2005

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG06F9/3802
  • WIPO fieldComputer technology
  • WIPO sectorElectrical engineering

Abstract

An instruction prefetch buffer control (20) is provided for an instruction prefetch buffer array (10) which stores the code for a number of instructions that have already been executed as well as the code for a number of instructions yet to be executed. The instruction prefetch buffer control includes a register (201) for storing an instruction fetch pointer, this pointer being supplied to the buffer array (10) as a write pointer which points to the location in the array where a new word is to be written from main memory. A second register (205) stores an instruction execution pointer which is supplied to the buffer array (10) as a read pointer. A first adder (203) increments the first register to increment the instruction fetch pointer for sequential instructions and calculates a new instruction fetch pointer for branch instructions. A second adder (215) increments the second register to increment the instruction execution pointer for sequential instructions and calculates a new instruction execution pointer for branch instructions. Incrementing of the second register is variable depending on the length of the instruction. A third adder ( 221) is responsive to the output of the fi…

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