Ati International Srl

S3 Incorporated, Inc.

Exponential Technology, Inc.

Cisco Technology, Inc.

Hal Computer Systems, Inc.

Advanced Silicon Technologies LLC

Shalesh Thusoo

Korbin S Van Dyke

Niteen Aravind Patkar

James S Blomgren

Stephen C Purcell

John S Yates, Jr

Paul Henry Hohensee

David Reese

T R Ramesh

Gurjeet Singh Saund

Gene Shen

Paul W Campbell

Tr Ramesh

Jaspal Kohli

Hao Wang

Don A Van Dyke

Ronak Patel

Govind V Malalur

Brian R Baird

David E Richter

Ali Alasti

Sanjay Mansingh

Sandeep Nijhawan

Farnad Sajjadian

Tiruvur R Ramesh

Dale R Jurich

Charles Akum Njinda

David L Reese

Jim Lin

Alan McNaughton

David M Stark

Betty Kikuta

Paul H Hohensee

Paul Campbell

A microprocessor chip has instruction pipeline circuitry, and instruction classification circuitry that classifies instructions as they are executed into a small number of classes and records a classification code value. An on-chip table has entries corresponding to a range of addresses of a memory and designed to hold a statistical assessment of a value of consulting an off-chip table in a memory of the computer. Lookup circuitry is designed to fetch an entry from the on-chip table as part of the basic instruction processing cycle of the microprocessor. A mask has a value set at least in part by a timer. The instruction pipeline circuitry is controlled based on the value of the on-chip table entry corresponding to the address of instructions processed, the current value of the mask, the recorded classification code, and the off-chip table.

Using on-chip and off-chip look-up tables indexed by instruction address to control instruction execution in a processor

A system with a single BIST for an IC that includes a number of memory arrays that may have varying latencies, widths, and depths. A serial bus (which may be a debug bus) connects the BIST controller, each of the memory arrays on the IC, and a controller. Each memory array has an associated Design for Test Assist Logic (DAL) block. The DAL associated with any particular memory array recognizes commands from the BIST that are for the associated memory array, controls the execution of write/read commands for the associated array and sends data read from the memory array along with appropriate commands to the comparator after a latency that is appropriate for the associated array Thus, there are standardized commands from the BIST, but each DAL executes these commands in a manner appropriate for the memory array (or arrays) associated with the particular DAL.

Area efficient BIST system for memories

A computer. When an instruction calling for an architecturally-visible side-effect in an architecturally-visible storage location is recognized, a value is stored representative of an architecturally-visible representation of the side-effect, a format of the representative value being different than an architecturally-visible representation of the side-effect. Execution is resumed without generating the architecturally-visible side-effect. Later, the architecturally-visible representation corresponding to the representative value is written into the architecturally-visible storage location. On a context switch, a context of a first process is written and a context of a second process is loaded to place the second process into execution. At least some instructions maintain results in storage resources outside the context resource set, and instructions are marked to indicate whether or not a context switch may be performed at a boundary of the marked instruction. Instruction execution is monitored for a condition that is a superset of a condition whose occurrence is desired to be detected, and a first exception is raised as a result of recognizing the superset condition. Software filters the superset condition to determine whether the monitored condition has occurred, and if so, the software establishes a second exception to be raised after execution of further instructions of the instruction stream. When it is recognized that an instruction is to affect the execution of a second instruction, the processor is set into single-step mode. After the second instruction is executed, the computer is set out of single-step mode.

Managing instruction side-effects

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

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 method and apparatus for out-of-order memory processing within an in-order processing device includes processing that allows a plurality of memory transactions to be processed in a pipeline manner until a dependency arises between two or more memory transactions. Such processing includes, for each of the plurality of memory transactions, determining whether data associated with the transaction is stored in local cache. If the data is stored in local cache, it is written into a data register in a next pipeline interval. The processing continues by storing the memory transaction in a miss buffer when the data associated with the memory transaction is not stored in the local cache. The processing continues by writing the associated data for the memory transaction identified in the missed buffer into the data register when the data is received without regard to the pipeline manner.

Method and apparatus for out of order memory processing within an in order processor

An integrated computing system includes at least one processor formed on a substrate, wherein the processor operates at a processor rate. The integrated computing system further includes a global bus that is coupled to the at least one processor and is formed on the substrate. The global bus supports transactions (e.g., data, operational instructions, and/or control signaling conveyances) at a rate that is equal to or greater than the processing rate. The integrated computing system further includes a device gateway and memory gateway that are operably coupled to the global bus and formed on the substrate. The device gateway provides an interface for at least one device (e.g., internal or external) to the global bus. The memory gateway provides an interface between the global bus and memory.

Method of manufacture and apparatus of an integrated computing system

A branch resolution logic for an in-order processor is provided which scans the stages of processor pipeline to determine the oldest branch instruction having sufficient condition codes for resolution. The stages are scanned in order from the latter stages to the earlier stages, which allows quick and simple branch resolution. Therefore, because branches are resolved as soon as the necessary condition codes are generated in a specific stage, branch mispredict penalties are minimized.

Multi-branch resolution

A method and apparatus for busing data elements within a computing system includes processing that begins by providing, on a shared bus, a first control signal relating to a first transaction during a first bus cycle. The processing continues by providing a second control signal relating to a second transaction and a first address signal relating to the first transaction during a second bus cycle. The processing continues by providing a third control signal relating to a third transaction and a second address signal relating to a second transaction during a third bus cycle. The processing then continues by providing a first status relating to the first transaction and a third addressing signal relating to the third transaction during a fourth bus cycle. The processing then continues by providing a second status relating to the second transaction during a fifth bus cycle. The processing then continues by providing first data relating to the first transaction when the first status is a hit and providing third status relating to the third transaction during a sixth bus cycle.

Method and apparatus for busing data elements

A method and apparatus for interfacing a processor with a bus includes processing that begins by storing transactions initiated by the processor into a buffer. The processing then continues by selecting one of the transactions stored in the buffer and placing the selected transaction on the bus. The processing continues by monitoring progress of fulfillment of each transaction in the buffer and flagging a transaction when it has been successfully completed. The processing also includes processing at least two related transactions prior to selecting one of the transactions from the buffer where, if transactions can be processed locally, they do not need to be transported on the bus. In addition, the processing includes monitoring the bus for related transactions initiated by another processor such that these transactions can be more efficiently processed. The related transaction on the bus would correspond to a transaction queued in the buffer.

Method and apparatus for interfacing a processor with a bus

A method and apparatus for both facilitating access to shared memory addresses over a common bus by a plurality of data processors includes detecting, by at least a first processor, that two access addresses are boundary addresses on either side of an address boundary. The method and apparatus locks the common bus in response to detecting the two access addresses. In addition, the method and apparatus locks the two detected addresses based on address probe inquiry data communicated by the first processor. Accordingly, at least one processor employs probe based bus lock and address lock control to facilitate efficient access to shared memory addresses. Preferably, each processor includes probe-based bus lock and address locking control. The method and apparatus provides a type of address locking with deterministic bus locking when needed.

Method and apparatus for providing probe based bus locking and address locking

A microprocessor die contains several processor cores and a shared cache. Trigger conditions for one or more of the processor cores are programmed into debug registers. When a trigger is detected, a trace record is generated and loaded into a debug queue on the microprocessor die. Several trace records from different processor cores can be rapidly generated and loaded into the debug queue. The external interface cannot transfer these trace records to an external in-circuit emulator (ICE) at the rate generated. The debug queue transfers trace records to the external ICE using a dedicated bus to the ICE so that bandwidth is not taken from the memory bus. The memory bus is not slowed for debugging, providing a more realistic debugging session. The debug buffer is also used as a video FIFO for buffering pixels for display on a monitor. The dedicated bus is connected to an external DAC rather than to the external ICE when debugging is not being performed.

Debug and video queue for multi-processor chip

A pipelined processor is modified to efficiently process repeated string instructions. A repeated string instruction repeats an iteration a number of times determined by a counter variable stored in a register file. Each iteration includes at least three pipeline flows to perform a load, store, or compare of a character in the string, and to decrement the counter variable. When the last flow of an iteration reaches the execute stage near the end of the pipeline, the current value of the counter variable is compared to the maximum number of iterations which may be present in the pipeline at one time. When the counter variable is equal to the maximum number of iterations, the execute stage signals the decode stage to stop dispatching iterations. The iterations in the pipeline are completed, providing the proper number of iterations. For short strings, the counter value may be less than the maximum number of iterations, and this is signaled to the decode stage, which flushes the pipeline once the current iteration completes. The decode stage does not need a copy of the counter variable, reducing dedicated hardware for processing repeated string instructions.

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Milpitas, CA, United States of America

Shalesh Thusoo