System for executing different cycle instructions by selectively bypassing scoreboard register and canceling the execution of conditionally issued instruction if needed resources are busy
US5185872A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 28, 1990 |
| Grant date | Feb 9, 1993 |
| Priority date | — |
| Expiry date | Feb 28, 2010 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F9/3838
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A scbok line is connected to a register file and other units, such as an execution unit and a multiply/divide unit, in a data processing system. A mem scbok line is connected to the register file and other units, such as an instruction unit and a memory interface unit. Each unit connected to the scbok line can pull the line to indicate that it is busy. Each unit connected to the mem scbok line can pull the line to indicate that it is busy. The scbok line indicates, when asserted, that a unit or a register in the register file that is busy with a previous instruction is not available to an instruction for a register file operation. The mem scbok line indicates, when asserted, that a unit or a register in the register file that is busy with a previous instruction is not available to an instruction for a memory operation. Registers are checked concurrently with the issuing of an instruction. An instruction lacking any needed unit or a register is stopped in response to the asserted scbok line and reissued in the next cycle. Registers to be used by a multi-cycle instruction are marked busy for an instruction that is able to be executed. When a result for the multi-cycle instruction ret…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.