Other

Stmicroelectronics Gmbh

Hewlett-Packard Company

Alexander J Starr

Paolo Faraboschi

Mark Owen Homewood

Geoffrey M Brown

Anthony Jarvis

Gary Lee Vondran, Jr

Richard L Ford

For use in a data processor comprising an instruction execution pipeline comprising N processing stages, a system and method of encoding constant operands is disclosed. The system comprises a constant generator unit that is capable of generating both short constant operands and long constant operands. The constant generator unit extracts the bits of a short constant operand from an instruction syllable and right justifies the bits in an output syllable. For long constant operands, the constant generator unit extracts K low order bits from an instruction syllable and T high order bits from an extension syllable. The right justified K low order bits and the T high order bits are combined to represent the long constant operand in one output syllable. In response to the status of op code bits located within a constant generation instruction, the constant generator unit enables and disables multiplexers to automatically generate the appropriate short or long constant operand.

System and method for encoding constant operands in a wide issue processor

There is disclosed a data processor comprising: 1) an instruction execution pipeline comprising N processing stages for executing a load instruction; 2) a status register for storing a modifiable configuration value, the modifiable configuration value having a first value indicating the data processor is capable of executing a misaligned access handling routine and a second value indicating the data processor is not capable of executing a misaligned access handling routine; 3) a misalignment detection circuit for determining if the load instruction performs a misaligned access to a target address of the load instruction and, in response to a determination that the load instruction does perform a misaligned access, generating a misalignment flag; and 4) exception control circuitry capable of detecting the misalignment flag and in response thereto determining if the modifiable configuration value is equal to the first value.

Circuit and method for supporting misaligned accesses in the presence of speculative load instructions

There is disclosed a data processor having a clustered architecture that comprises a plurality of clusters and an interrupt and exception controller. Each of the clusters comprises an instruction execution pipeline having N processing stages. Each of the N processing stages is capable of performing at least one of a plurality of execution steps associated with instructions being executed by the clusters. The interrupt and exception controller operates to (i) detect an exception condition associated with one of the executing instructions, wherein this executing instruction issued at time t , and (ii) generate an exception in response to the exception condition upon completed execution of earlier ones of the executing instructions, these earlier executing instructions issued at time preceding t .

System and method for supporting precise exceptions in a data processor having a clustered architecture

A cache flush controller, and an associated method, selectably flushes a memory cache of a data processor. The cache flush controller operates at a memory bus level of the data processor and operates to flush a selected line, or lines of the memory cache by writing arbitrary, selected values to the selected line or lines of the memory cache.

Growing community of inventors

Acton, MA, United States of America

Alexander J Starr