Ati International Srl

Ati Technologies Ulc

Ati Technologies Inc.

Ikanos Communications, Inc.

T R Ramesh

Korbin S Van Dyke

John S Yates, Jr

Paul Henry Hohensee

David Reese

Shalesh Thusoo

Niteen Aravind Patkar

Gurjeet Singh Saund

Stephen C Purcell

Behrooz Rezvani

Paul W Campbell

Ronak Patel

Avadhani Shridhar

Firooz Massoudi

Raminder Singh Bajwa

Masoud Eskandari

Omprakash S Sarmaru

Alan McNaughton

Greg L Ries

A computer. A processor pipeline alternately executes instructions coded for first and second different computer architectures or coded to implement first and second different processing conventions. A memory stores instructions for execution by the processor pipeline, the memory being divided into pages for management by a virtual memory manager, a single address space of the memory having first and second pages. A memory unit fetches instructions from the memory for execution by the pipeline, and fetches stored indicator elements associated with respective memory pages of the single address space from which the instructions are to be fetched. Each indicator element is designed to store an indication of which of two different computer architectures and/or execution conventions under which instruction data of the associated page are to be executed by the processor pipeline. The memory unit and/or processor pipeline recognizes an execution flow from the first page, whose associated indicator element indicates the first architecture or execution convention, to the second page, whose associated indicator element indicates the first architecture or execution convention. In response to the recognizing, a processing mode of the processor pipeline or a storage content of the memory adapts to effect execution of instructions in the architecture and/or under the convention indicated by the indicator element corresponding to the instruction's page.

Computer for executing two instruction sets and adds a macroinstruction end marker for performing iterations after loop termination

A microprocessor chip, and methods for use in that microprocessor chip. The chip has instruction pipeline circuitry and address translation circuitry. Table lookup circuitry indexes into a table, the table having an entry associated with each corresponding address range translated by the address translation circuitry. Each entry of the table describes a likelihood of the existence of an alternate coding of instructions located in the respective corresponding address range. The table lookup circuitry retrieves a table entry corresponding to the address, and is operable as part of the basic instruction cycle of executing an instruction of a non-supervisor mode program executing on a computer. Interrupt circuitry is cooperatively designed with the instruction pipeline circuitry to trigger an interrupt on execution of an instruction of a process, synchronously based at least in part on a memory state of the computer and the address of the instruction, the architectural definition of the instruction not calling for an interrupt. A handler for the interrupt is responsive to the contents of the table to affect the instruction pipeline circuitry to effect control of an architecturally-visible data manipulation behavior or control transfer behavior of the instruction based on the contents of a table entry associated with the instruction.

Side tables annotating an instruction stream

A method and a computer for performance of the method. While executing a program on a computer, profileable events occurring in the instruction pipeline are detected. The instruction pipeline is directed to record profile information describing the profileable events essentially concurrently with the occurrence of the profileable events. The detecting and recording occur under control of hardware of the computer without software intervention.

Profiling execution of computer programs

A computer. An instruction pipeline and memory access unit execute instructions in a logical address space of a memory of the computer. An address translation circuit translates address references generated by the program from the program's logical address space to the computer's physical address space. Profile circuitry is cooperatively interconnected with the instruction pipeline and configured to detect, without compiler assistance for execution profiling, occurrence of profilable events occurring in the instruction pipeline, and is cooperatively interconnected with the memory access unit to record profile information describing physical memory addresses referenced during an execution interval of the program.

Profiling of computer programs executing in virtual memory systems

A computer has a multi-stage execution pipeline and an instruction decoder. The instruction decoder is designed (a) to decode instructions of a complex instruction set for execution by the pipeline, the instruction set being architecturally exposed for execution by user-state programs stored in a main memory of the computer, the instruction set having variable-length instructions and many instructions having multiple side-effects and a potential to raise multiple exceptions, (b) for at least some instructions of the complex instruction set, to issue two or more instructions in a second internal form into the execution pipeline; (c) to generate information descriptive of instructions to be executed by the pipeline, and to store the information into non-pipelined processor registers of the computer; and (d) to determine whether instructions will complete in the pipeline, and to abstain from writing descriptive information into the processor registers for instructions following an instruction determined not to complete. The pipeline exception circuitry is designed to recognize an exception occurring in an instruction after a first side-effect of the instruction has been architecturally committed, and thereupon, to architecturally expose in the processor registers information describing a processor state of the computer, including an intra-instruction program counter value, and to transfer execution to an exception handler. Pipeline resumption circuitry is effective, after completion of the software exception handler, to resume execution of the excepted program based on the information in the processor registers. The processor registers of the computer are designed to architecturally expose sufficient information about the state of the excepted instruction that the transfer and resume are effected without saving processor state to the main memory, the processor registers and general purpose registers of the computer together providing sufficient working storage for execution of the exception handler and resumption of the program, without storing processor state to the main memory.

Exception mechanism for a computer

The current invention provides a digital signal processor which supports multiple X-DSL protocols and a multiplicity of channels on a single chip. Each channel is packetized and each packet includes control information for controlling the performance of the components/modules on the transmit and receive path. Further flexibility is derived from an architecture which incorporates discrete and shared modules on the transmit path and the receive path. The transmit path and receive path modules are collectively controlled by control information in selected ones of the packets and operate on each channel's packets at an appropriate rate, and protocol for the channel. A digital signal processor (DSP) is disclosed which incorporates these features. The DSP exhibits a favorable form factor, and flexibility as to protocols and line codes, and numbers of channels supported.

Method and apparatus for synchronizing a packet based modem supporting multiple X-DSL protocols

A method and computer for performance of the method. While executing a program on a computer, the computer uses registers of a general register file for storage of instruction results. Profile information describing the profileable events is recorded into the general register file as the profileable events occur, without first capturing the information into a main memory of the computer.

Profiling program execution into registers of a computer

A multiple instruction set processor and method dynamically activates one of a plurality of branch prediction processes depending upon which one of a multiple instruction set is operational. Shared branch history table structures are used and are indexed differently depending upon which instruction set is operational. The apparatus and method also allows switching between instruction set index generators for each of the plurality of instruction sets. Accordingly, different indexes to branch prediction data are used depending upon which of the plurality of instruction sets is operational. Shared memory may be used to contain branch prediction table data for instructions from each of the plurality of instruction sets in response to selection of an instruction set. Shared memory is also used to contain branch target buffer data for instructions from each of the plurality of instruction sets in response to selection of one of the instruction sets.

Switching between a plurality of branch prediction processes based on which instruction set is operational wherein branch history data structures are the same for the plurality of instruction sets

An instruction aligner and method evaluates a fixed length instruction cache line by breaking it into at least two components. These two components, in one embodiment, include half of the instruction cache line being designated as most significant bytes and the second half of the instruction cache line being designated as least significant bytes. A byte right rotator is responsible for feeding the next sixteen bytes of the instruction stream, while a byte right shifter shifts the unused bytes of the current sixteen bytes the aligner is working on. The byte rotator and byte shifter combine to provide aligned variable length instructions for decoding based on either a fetch PC value or current instruction length.

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Newark, CA, United States of America

T R Ramesh