Hitachi, Ltd.

Kazunori Kuriyama

Yooichi Shintani

Akira Yamaoka

Kiyoshi Inoue

Kenichi Wada

Eiki Kamada

Tohru Shonai

Naohiko Irie

Moritoshi Yasunaga

Hiroshi Kurokawa

Hiroaki Odawara

An information processing apparatus in which instructions are processed one by one conceptually and results thereof are conceptually orderly written into a memory comprises an instruction control circuit capable of decoding M instructions and reading operands in parallel, N (N.gtoreq.M) execution circuits capable of executing a plurality of instructions mutually in parallel, a detection circuit for determining whether all of M execution circuits of the N execution circuits required by the M instructions decoded by the instruction control circuit are vacant or not, and a reserve circuit for reserving the execution of the M decoded instruction while the detection fails to detect sufficient vacancy.

Information processing system and information processing method for

A data processor transfers files at high speeds from a magnetic disk or other storage media to a network and shortens the processing time for the file transfers. An I/O processor includes (i) a channel to which a magnetic disk is connected, (ii) a LAN adapter to which a network is connected, (iii) a switch for switching and connecting the channel and LAN adapter, and (iv) a channel controller for controlling the channel, the LAN adapter, and the switch. The channel controller controls the channel, the LAN adapter, and the switch in accordance with a data transfer start instruction from an instruction processor. The channel reads data from the magnetic disk and transfers it to the LAN adapter via the switch. The LAN adapter sends the data to the network or reads data from the network and transfers it to the channel via the switch. The channel sends the data to the magnetic disk.

Computer system with an input/output processor which enables direct file

An auxiliary data processor having an built-in multi-entry data memory is directly connected to a main storage, and executes, directly accessing the main storage, commands sent from a plurality of instruction processors. One data memory entry is assigned to an instruction processor that issued a command, and reserves data fetched from the main storage in response to the command so that the next command can use part of that data. A tag circuit holds an identifier of each instruction processor to which a data memory entry has been assigned and the address and length of data hold in that entry, and see that each command uses the reserved data correctly. Each instruction processor selects commands to be sent to the auxiliary data processor depending upon the conditions of operands. A large amount of data is processed at a high rate, minimizing cache pollution.

Computers having cache memory

An information processor detects a conflict between successive instructions by determining whether a preceding instruction under execution calls for fetching a first operand from a main memory, generating execution result data based on the first operand and updating one of a plurality of address data designated by a to-be-executed succeeding instruction, with the execution result data. When a conflict is detected, there is supplied to an address adder at least some of the plurality of address data determined by a type of the preceding instruction to complete an operand address calculation stage for the succeeding instruction. Then, before the one address data is updated by the preceding instruction after the first operand has been fetched from the main memory in an operand fetch stage for the preceding instruction, an operation determined by the preceding instruction is performed on the output of the address adder and the fetched first operand to generate an address equal to a sum of the plurality of address data, excluding said one address, and the execution result data for the preceding instruction, and this address is used as the address of the second operand of the succeeding instruction.

Information processor providing enhanced handling of address-conflicting

An instruction processor effecting operations for register operands and for processing branch instructions to perform address calculations for branch destination instructions, comprising general-purpose registers storing data including results of operations of said instruction processor, address adders calculating the address of branch destination instructions by using data read out from the general-purpose register and an ALU performing arithmetical or logical operations on the data read out from the general-purpose register in the decode cycle of the instructions. The result of the arithmetical or logical operation is inputted into the address adder but not from the general-purpose register, in the case where the result of the arithmetical or logical operation is utilized for address calculation in the execution of a succeeding instruction.

Instruction processor for processing branch instruction at high speed

Data processor for concurrent executing of instructions by plural

A data processor includes an instruction detection unit for detecting that a succeeding instruction writes a read-out operand into a general register group without subjecting it to arithmetic or logical operation, in accordance with instruction decode informations provided by an instruction hold unit; a conflict detection unit for detecting a conflicting state that the preceding instruction performs a write operation into a general register of the general register group and the succeeding instruction reads an operand from the same general register, in accordance with instruction decode informations provided by the instruction hold unit; and a contention detection unit for detecting a contention state that the preceding instruction performs a write operation into the same general register and the succeeding instruction also performs a write operation into the same general register, in accordance with instruction decode informations provided by the instruction hold unit.

Data processor for parallelly executing conflicting instructions

Address calculation adders and a buffer storages are each independently provided for each operand of an instruction requiring two or more operands. In the translation instruction processing, the address calculations and operand fetch operations on the first and second operands are substantially asynchronously conducted. Consequently, the overhead that takes place one every n second operand fetch operations can be removed by independently and asynchronously performing the address calculations and operand fetch operations by use of a plurality of address adders. Moreover, the circuit for separating and obtaining a byte from the operand buffer can be dispensed with by adopting an operation procedure in which a byte of the first operand is fetched and is stored in temporary store means that supplies the address adder the data stored therein.

Pipelined instruction processor capable of reading dependent operands in

A data processing apparatus of processing first instruction of a type in which the result of operation of the first instruction is stored in at least one storage location designated by operands of the first instruction and second instruction of a type which succeeds to the first instruction and makes use of the result of operation of the first instruction as operand data. The apparatus comprises an OSC control circuit for detecting whether at least a part of the result of operation of the first instruction is to be used or not as the operand data for the second instruction, and an arithmetic unit for allowing the result of operation of the first instruction to be directly used as the operand data for the second instruction when the OSC control circuit detects the given condition is fulfilled.

Pipelined parallel data processing apparatus for directly transferring

A pipelined data processor comprises a circuit for storing two instructions in a pair of instruction registers, a circuit for detecting whether those instructions are a combination of an instruction requesting the use of an operation unit and an instruction requesting the use of another resource, and a circuit to control the execution of the instructions when the decision of the detection circuit is affirmative such that those instructions are executed by the operation unit and the resource in a plurality of stages.

Pipelined data processor capable of decoding and executing plural

An information processing apparatus having a buffer register for pre-fetching a plurality of instructions and executing one instruction after another by reading them from the buffer registers, is provided with a first instruction decode start determination unit for register type instructions and a second instruction decode start determination unit for non-register type instructions, provided separately from the first unit, whereby 0.5 cycle after a register type instruction starts being decoded, or 1 cycle after a non-register type instruction starts being decoded, the next instruction starts to be decoded. By decoding a register type instruction at high speed, it becomes possible to execute a branch instruction at high speed.

Information processing apparatus

A decimal multiplier device including a register A storing the multiplier, a register B storing the multiplicand, a shifter for outputting the output of the register A as it is or after having been shifted, based on a first signal, a gate for outputting the output of the register B or '0', based on a second signal, an adder/subtractor for adding the output of the shifter and that of the gate and storing the result thus obtained in the register A, and a decoder for receiving the value of a selected digit of the content of the register A and controlling the gate and the shifter by generating the first signal and the second signal based on the received value so that the multiplicand B is added n times, n corresponding to the received value, to the content of the register A or substracted (10-n) times therefrom. The register A, the shifter and the adder/subtractor form a single loop. Decimal multiplication is performed by controlling the shifter, when signals pass through the loop repeatedly.

Decimal multiplier device and method therefor

This invention employs a construction in which subtraction processing and digit shift processing in decimal division are carried out in parallel with each other to shorten the time required for decimal division. A dividend is stored in a register B and a divisor, in a register C. A selector 6 selects register B when the result of subtraction by an adder/subtracter 1 is positive or zero, and selects register A at other times. Both adder/subtracter 1 and a shifter 2 receive the signal from the selector 6 in the same way, and execute the subtraction processing and the shift processing, respectively. The results of these processings are stored in the registers B and A', respectively. The division time can be shortened because the adder/subtracter 1 and the shifter 2 can be actuated simultaneously.

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Saitama, Japan

Kazunori Kuriyama