Memory stream buffer with variable-size prefetch depending on me

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395405, 395416, 39542103, 364960, 3649631, 3649661, G06F 710

Patent

active

056597134

ABSTRACT:
A read buffering system and method employs a bank of FIFOs to hold sequential read data for a number of data streams being fetched by a computer. The FIFOs are located in the memory controller, so the system bus is not used in the memory accesses needed to fill the stream buffer. The buffer system stores addresses used for read requests made by a CPU, and if a next sequential address is then detected in a subsequent read request, this is designated to be a stream (i.e., sequential reads). When a stream is thus detected, data is fetched from DRAM memory for addresses following the sequential address, and this prefetched data is stored in one of the FIFOs. A FIFO is selected using a least-recently-used algorithm. When the CPU subsequently makes a read request for data in a FIFO, this data can be returned without making a memory access, and so the access time seen by the CPU is shorter. By taking advantage of page mode, access to the DRAM memory for the prefetch operations can be transparent to the CPU, resulting in substantial performance improvement if sequential accesses are frequent. One feature is appending page mode read cycles to a normal read, in order to fill the FIFO. The data is stored in the DRAMs with ECC check bits, and error detection and correction (EDC) is performed on the read data downstream of the stream buffer, so the data in the stream buffer is protected by EDC.

REFERENCES:
patent: 3898624 (1975-08-01), Tobias
patent: 4086629 (1978-04-01), Desyllas et al.
patent: 4292674 (1981-09-01), Scheuneman
patent: 4371924 (1983-02-01), Schaefer et al.
patent: 4489378 (1984-12-01), Dixon et al.
patent: 4533995 (1985-08-01), Christian et al.
patent: 4536836 (1985-08-01), Dodd et al.
patent: 4621320 (1986-11-01), Holste
patent: 4807110 (1989-02-01), Pomerene et al.
patent: 4918587 (1990-04-01), Pechter et al.
patent: 4980823 (1990-12-01), Liu
patent: 5003471 (1991-03-01), Gibson
patent: 5146578 (1992-09-01), Zangenehpour
patent: 5257370 (1993-10-01), Letwin
patent: 5261066 (1993-11-01), Jouppi
patent: 5345560 (1994-09-01), Miura et al.
patent: 5371870 (1994-12-01), Goodwin et al.
patent: 5461718 (1995-10-01), Tatosian et al.
Bennett, B.T., and C. May "Improving Performance of Buffered DASD to Which Some References are Sequential." IBM Technical Disclosure Bulletin,vol. 24, No. 3, Aug. 1981.

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