Sun Microsystems, Inc.

Silicon Graphics, Incorporated

Transmeta Corporation

Other

Mips Technologies, Inc.

Andre Kowalczyk

Marc R Tremblay

Robert Paul Masleid

Anup S Tirumala

Givargis George Kaldani

Norman K Yeung

Anup S Tirumula

A circuit for assisting signal transitions on a wire, and a method thereof. The circuit includes a first subcircuit that causes a first transistor that is coupled to the circuit's output to turn on during a rising transition and then turn off. The first transistor drives the output to a high state to assist in the rising transition. The circuit also includes a second subcircuit that causes a second transistor that is coupled to the circuit's output to turn on during a falling transition and then turn off. The second transistor drives the output to a low state to assist in the falling transition.

Circuits and methods for detecting and assisting wire transitions

A method and computer system for resolving simultaneous requests from multiple processing units to load from or store to the same shared resource. When the colliding requests come from two different processing units, the first processing unit is allowed access to the structure in a predetermined number of sequential collisions and the second device is allowed access to the structure in a following number of sequential collisions. The shared resource can be a fill buffer, where a collision involves attempts to simultaneously store in the fill buffer. The shared resource can be a shared write back buffer, where a collision involves attempts to simultaneously store in the shared write back buffer. The shared resource can be a data cache unit, where a collision involves attempts to simultaneously load from a same data space in the data cache unit. A collision can also involve an attempt to load and store from a same resource and in such case the device that attempts to load is favored over the device that attempts to store.

Arbitration protocol for a shared data cache

A shared write back buffer for storing data from a data cache to be written back to memory. The shared write back buffer includes a plurality of ports, each port being associated with one of a plurality of processing units. All processing units in the plurality share the write back buffer. The shared write back buffer further includes a data register for storing data provided through the input ports, an address register for storing addresses associated with the data provided through the input ports, and a single output port for providing the data to the associated addresses in memory.

Shared write buffer for use by multiple processor units

A system and method for fetching instructions for use in a RISC processor having an on-chip instruction cache is disclosed. The system accesses a first group of instructions having a first set of ordered addresses and a second group of instructions having a second set of ordered addresses, simultaneously, from an instruction cache. The first group of instructions is to be executed during a first cycle and the second group of instructions is to be executed during a second cycle. The technique transfers the first group of instructions to an instruction decoder for execution during the first cycle and transfers the second group of instructions to the instruction decoder for execution during the second cycle. The technique reduces the power consumed by memory modules and support circuitry of the instruction cache by requiring instruction cache accesses only every other cycle.

System and method for fetching multiple groups of instructions from an

A RISC processor utilizes a segmented cache to reduce word line loading to reduce power consumption and increase speed. Address bit are predecoded to activate a selected segment. Groups of instructions are accessed from the cache in parallel and stored in register. The stored instructions are fetched from the register during sequential instruction execution to reduce the number of cache accesses.

RISC processor having improved instruction fetching capability and

A 64-bit wide unified integer and floating-point datapath for a RISC processor. The unified datapath allows for the sharing of some of the major hardware resources within the integer and floating-point execution units, as well as simplifying a large portion of the peripheral circuitry. The unified datapath results in a more efficient use of the hardware with reduced average power dissipation and area, without compromising the major performance advantages of RISC processors.

Growing community of inventors

San Jose, CA, United States of America

Andre Kowalczyk