Fast cache flush mechanism

Details Fast cache flush mechanism Fast cache flush mechanism

1981-05-22

1984-01-17

Smith, Jerry

Boots, shoes, and leggings

G06F 1300

Patent

active

044266820

ABSTRACT:
A fast cache flush mechanism includes, associated with the cache, an auxiliary portion (termed a flush count memory) that references a flush counter during the addressing of the cache. This flush counter preferably has a count capacity of the same size as the number of memory locations in the cache. Whenever the cache is updated, the current value of the flush counter is written into the location in the flush count memory associated with the memory location in the cache pointed to by an accessing address, and the valid bit is set.
Whenever it is desired to flush the cache, the contents of the flush counter are changed (e.g. incremented) to a new value which is then written as the new cache index into the location of the flush count memory associated with that flush count, and the associated valid bit is cleared or reset. Any access to the cache by the address requires that the cache index in the associated flush count memory location match the current contents of the flush counter and that the valid bit be set. When the cache is flushed by the above procedure, these conditions cannot be fulfilled, since the current contents of the flush counter do not match any cache index or the valid bit has been reset. As a result, for each addressed memory location that has not been accessed since the last cache flush command (corresponding to the latest incrementing of the flush counter), the total contents of that memory location (i.e. data, cache index and validity bit) are updated in the manner described above. Through this procedure, once the contents of the flush counter have recycled back to a previous value, it is guaranteed that each memory location in the cache will have been flushed and, in many instances, updated with valid data.

REFERENCES:
patent: 3541529 (1970-11-01), Nelson
patent: 3588829 (1971-06-01), Boland et al.
patent: 3800286 (1974-03-01), Brown et al.
patent: 3840862 (1974-10-01), Ready
patent: 3845474 (1974-10-01), Lange et al.
patent: 3896419 (1975-07-01), Lange et al.
patent: 4056844 (1977-11-01), Izumi
patent: 4092713 (1978-05-01), Scheuneman
patent: 4095269 (1978-06-01), Kawabe et al.
patent: 4142234 (1979-02-01), Bean et al.
patent: 4167782 (1979-09-01), Joyce et al.
patent: 4168541 (1979-09-01), DeKarske
patent: 4169284 (1979-09-01), Hogan et al.
patent: 4181937 (1980-01-01), Hattori et al.
patent: 4197580 (1980-04-01), Chang et al.
patent: 4228503 (1980-10-01), Waite et al.
patent: 4314331 (1982-02-01), Porter et al.

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