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公开(公告)号:DE68923818D1
公开(公告)日:1995-09-21
申请号:DE68923818
申请日:1989-04-11
Applicant: IBM
Inventor: BLAND PATRICK MAURICE , KRAMER KEVIN GERRARD , DEAN MARK EDWARD , TEMPEST SUSAN LYNN , GAUDENZI GENE JOSEPH
IPC: G06F11/10 , G06F13/38 , G06F13/40 , H03K3/288 , H03K19/082 , H03K19/00 , H03K19/0175
Abstract: A circuit for buffering and parity checking digital data communicated between first and second data buses includes a plurality of bidirectional bit buffer circuits. Each of the bidirectional bit buffer circuits includes : a first data path comprising a data receiver, latch, and driver connected in series between the first and second data buses, respectively; a second data patch comprising a data receiver, latch and driver connected in series between the second and first data buses, respectively; control mechanism for controlling the drivers to selectively place the output of the drivers in an active driving or high impedance state; and control mechanisms for controlling the data latches to selectively latch or pass through data. A parity generating circuit is connected at the output of the latch in the first data path of each of the bidirectional bit buffer circuits for generating a parity bit responsive to the data at the output of these latches. A transparent and driver circuit with phase splitter are provided for increasing the speed of the circuit without substantially increasing the power requirements.
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公开(公告)号:IN174948B
公开(公告)日:1995-04-01
申请号:IN444DE1989
申请日:1989-05-19
Applicant: IBM
Inventor: BLAND PATRICK MAURICE , DEAN MARK EDWARD , BEGUN RALPH MURRAY
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公开(公告)号:DK169492B1
公开(公告)日:1994-11-07
申请号:DK189489
申请日:1989-04-19
Applicant: IBM
Inventor: BEGUN RALPH MURRAY , BLAND PATRICK MAURICE , DEAN MARK EDWARD
Abstract: In a microcomputer system comprising a microprocessor and a cache subsystem and operable in a pipelined mode, there is potential incompatibility between pipelined operations and dynamic bus sizing as the cache subsystem operates with a fixed size data width and dynamic bus sizing allows the system to operate with devices of differing data width. This incompatibility is accommodated by the present system by defining certain addresses as cacheable addresses and other addresses as non-cacheable addresses and ensuring that addresses of devices of data width different from the cache data width are non-cacheable. An address decoder provides a control signal indicating whether or not a generated address is within the cacheable range. This control signal controls a next address signal applied to the microprocessor, which signal allows the processor to proceed to a following cycle prior to the end of the current cycle. Whenever a non-cacheable address is detected, the next address signal is suppressed.
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公开(公告)号:MX170835B
公开(公告)日:1993-09-20
申请号:MX1616989
申请日:1989-05-24
Applicant: IBM
Inventor: BEGUN RALPH MURRAY , BLAND PATRICK MAURICE , DEAN MARK EDWARD
Abstract: In a dual bus microcomputer system using a cache memory and a cache controller, the timing requirements placed on non-cache memory components by the cache controller are more stringent than the timing requirements placed on the non-cache memory components by the microprocessor. A logic circuit operates on the cache write enable (CWE) signals, and delays those signals in the event of a cache read miss. Delaying the CWE signals relaxes the timing requirements placed on non-cache memory components and at the same time does not impact wait state parameters for read miss operations.
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公开(公告)号:FI914608A
公开(公告)日:1992-04-02
申请号:FI914608
申请日:1991-10-01
Applicant: IBM
Inventor: ALDEREGUIA ALFREDO , BLAND PATRICK MAURICE , CROMER DARYL CARVIS , STUTES ROGER MAX
IPC: G11C11/401 , G06F12/00 , G06F12/02 , G06F12/06 , G06F13/42 , G11C11/407 , G11C
Abstract: A data processing system includes a memory controller for accessing a dynamic memory having a plurality of SIMMs that differ in size and speed of operation. The memory controller is operable in response to a request to access a given SIMM to read a SIMM definition register and dynamically produce memory access signals in accordance with the timing requirements of the particular SIMM being accessed. Such signals are set each time a SIMM is accessed. The signals provide different clock periods of RAS precharge time, RAS to CAS time, and CAS pulse width.
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公开(公告)号:FR2632096B1
公开(公告)日:1991-09-20
申请号:FR8905077
申请日:1989-04-11
Applicant: IBM
Inventor: BLAND PATRICK MAURICE , DEAN MARK EDWARD , MILLING PHILIP ERNA
IPC: G06F9/44 , G06F9/445 , G06F13/36 , G06F13/362 , G06F13/42
Abstract: A multi-bus microcomputer system includes a cache subsystem and an arbitration supervisor. A CPU is provided with a PREEMPT signal source which generates a preempt signal in CPU cycles extending beyond a specified duration. The preempt signal is effective at any device having access to the bus to initiate an orderly termination of the bus usage. When that device signals its termination of bus usage, the arbitration supervisor changes the state of an ARB/GRANT conductor, which had been in the grant phase, to the arbitration phase. During the arbitration phase each of the devices (other than the CPU) cooperates in an arbitration mechanism for bus usage during the next grant phase. On the other hand, the CPU, having asserted preempt, responds to a signal indicating initiation of the arbitration phase by immediately accessing the system bus.
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公开(公告)号:AU611275B2
公开(公告)日:1991-06-06
申请号:AU3246589
申请日:1989-04-05
Applicant: IBM
Inventor: BLAND PATRICK MAURICE , DEAN MARK EDWARD
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公开(公告)号:GB2219111B
公开(公告)日:1991-05-29
申请号:GB8912019
申请日:1989-05-25
Applicant: IBM
Inventor: BEGUN RALPH MURRAY , BLAND PATRICK MAURICE , DEAN MARK EDWARD
IPC: G06F12/08
Abstract: In a dual bus microcomputer system using a cache memory and a cache controller, the timing requirements placed on non-cache memory components by the cache controller are more stringent than the timing requirements placed on the non-cache memory components by the microprocessor. A logic circuit operates on the cache write enable (CWE) signals, and delays those signals in the event of a cache read miss. Delaying the CWE signals relaxes the timing requirements placed on non-cache memory components and at the same time does not impact wait state parameters for read miss operations.
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公开(公告)号:BE1002653A4
公开(公告)日:1991-04-23
申请号:BE8900440
申请日:1989-04-20
Applicant: IBM
Inventor: BEGUN RALPH MURRAY , BLAND PATRICK MAURICE , DEAN MARK EDWARD
IPC: G06F12/08
Abstract: Dans un système de micro-calculateur 80386/82385, les exigences de chronologie relatives aux éléments de mémoire sans possibilité d'antémémoire et placées par l'unité 82385 sont plus restrictives que les tolérances de chronologie placées sur les composants de mémoire sans possibilité d'antémémoire par l'unité 80386. La présente invention fonctionne sur les signaux de conditionnement d'écriture (CWE) d'antémémoire 82385 et retarde les signaux dans le cas d'une lecture manquée. Le retardement des signaux CWE élargit les tolérances de chronologie placée sur les composants de mémoire sans possibilité d'antémémoire et en même temps, n'affecte pas les paramètres d'état d'attente relatifs aux opérations de lecture manquée.
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公开(公告)号:PE8691A1
公开(公告)日:1991-03-22
申请号:PE17091290
申请日:1990-06-18
Applicant: IBM
Inventor: BLAND PATRICK MAURICE , DEAN MARK EDWARD , BEGUN RALPH MURRAY
IPC: G06F13/36 , H03K19/00 , G06F13/28 , G06F13/362
Abstract: RELACIONADOS A CIRCUITOS DE COMPUTADORA EN ESPECIAL A UN CIRCUITO LOGICO PARA COLOCAR A UNA MICROPROCESADORA EN UN ESTADO DE RETENCION, EN RESPUESTA A UNA SENAL DE REQUISICION DE RETENCION, Y A FIN DE BLOQUEAR LA MICROPROCESADORA PARA EL COLECTOR LOCAL DE LA UNIDAD CENTRAL DE PROCESAMIENTO (CPU) POR UN PERIODO MINIMO PREDETERMINADO
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