Abstract: A main storage apparatus is a synchronous dynamic memory having a plurality of memory banks and a node register for determining an operation mode, a main storage controller is coupled to a processor and the main storage apparatus, and means to realize controlling of parallel access to a plurality of banks of the memory and controlling of setting of an operation mode to the built-in register is arranged in the main storage controller. Accordingly, the use of a conventional processor of high generality and a conventional memory can be ensured.

Abstract: A processor for use in a data processing system with a cache RAM and main memory has a control pin for deactivating the driving of the data bus without deactivating that of the address bus during a write cycle. This capability is useful during a cache storing operation following a miss for performing a write operation without the requirement of additional address storing circuitry. In particular, during a cache storing operation, the processor can drive the address bus while control of the data bus by the processor is floated. Then, the data in main memory can be put on the data bus and transferred into the cache memory. Once the data is transferred to the cache memory, the original write operation can be completed.

Abstract: A multiprocessor system of the present invention has an address bus, a data bus, first and second processors, four access queues, and a shared memory divided into four banks. The four access queues are constituted by first-in first-out memories for buffering a plurality of access-request addresses transmitted through the address bus. Even if continuous access requests are addressed to one bank of the shared memory, a succeeding access request need not wait for a previous access request to be finished. Accordingly, the throughput of the system can be improved greatly.

Abstract: A data processor is provided with a first register storing a first half word of one instruction; a second register storing a second half word of the instruction; a first decoder decoding the first half word and at the same time detecting whether there exists an addressing extension portion between the first half word and the second half word; a second decoder decoding the second half word; and, a decode result generating circuit, to which a detection signal of the first decoder indicates whether the addressing extension portion exists. A decode result of the first decoder and a decode result of the second decoder are supplied to the decode result generating circuit. An extension portion register is provided to store the addressing extension portion. When the first decoder detects the addressing extension portion, the decode result generating circuit invalidates the decode result of the second decoder.

Abstract: A non-shared system with respect to an outside and an inside cache in a multi-processor system has multi-layer hierarchical cache. An invalidation address on a main memory address bus 31 in company with the rewriting of a main memory 30 is transmitted via a first and a second path 35, 36 to inside caches 11,21 so as to invalidate these inside caches 11, 21. The invalidation address is transmitted to the outside caches 12, 22 via the bidirectional connections between the main memory address bus 31 and outside caches 12, 22 so as to invalidate these outside caches 12, 22. It is extremely improbable for the address of access for writing to the transmitted to the main memory address bus 31 because the outside caches 12, 22 are operated in either copy back or write once system.

Abstract: Herein disclosed is a multiprocessor system which comprises first and second processors (1001 and 1002), first and second cache memories (100:#1 and #2), an address bus (123), a data bus (126), an invalidating signal line (PURGE:131) and a main memory (1004). The first and second cache memories are operated by the copy-back method. The state of the data of the first cache (100:#1) exists in one state selected from a group consisting of an invalid first state, a valid and non-updated second state and a valid and updated third state. The second cache (100:#2) is constructed like the first cache. When the write access of the first processor hits the first cache, the state of the data of the first cache is shifted from the second state to the third state, and the first cache outputs the address of the write hit and the invalidating signal to the address bus and the invalidating signal line, respectively.

Abstract: A static memory cell is connected with word lines and data lines. First and second switches are connected in series between a data line and on output circuit. A sense amplifier has an input/output terminal connected to a common connection point of the said first and second switches. The first switch is turned off in synchronism with commencing operation of the sense amplifier such that the parasitic capacitance of the data line as viewed from the sense amplifier decreases. The second switching means is turned on a predetermined time later in order to transmit the output signal of the sense amplifier to the output circuit.

Abstract: A static memory cell is connected with word lines and data lines. First and second switches are connected in series between a data line and an output circuit. A sense amplifier has an input/output terminal connected to a common connection point of the said first and second switches. The first switch is turned off in synchronism with commencing operation of the sense amplifier such that the parasitic capacitance of the data line as viewed from the sense amplifier decreases. The second switching means is turned on a predetermined time later in order to transmit the output signal of the sense amplifier to the output circuit.