Boots – shoes – and leggings
Patent
1991-12-30
1993-10-05
Fleming, Michael R.
Boots, shoes, and leggings
395275, 3642384, 3642423, 36424231, 3642476, 3642477, 3642481, 364251, 3642515, 364260, 3642608, 3642624, 3642625, 364DIG1, G06F 1300
Patent
active
052513122
ABSTRACT:
In the system of the present invention, the limitations imposed by the physical limitations of the DMA controller are overcome by storing the channel control blocks in external memory. The DMA controller is programmed to reference a particular address of external memory when a predetermined bit in the current channel control block is set. The DMA controller will then perform a memory read operation on the area of memory referred to by that address in order to store the retrieved channel control block at a location previously utilized by a earlier channel control block. This reading process will continue until the bit is reset, at which time the DMA operation is complete. Dynamic chaining is accommodated whereby the channel control blocks can be dynamically changed during the DMA access to provide a flexible I/O system. Furthermore, a method and apparatus for implementing dynamic chaining without incurring race conditions is described. A wait bit in each channel control block is provided when this bit is set, the DMA controller will suspend operations thereby providing opportunity for updating the chain of CCBs without incurring errors due to race conditions. Once the chain has been modified, the wait bit is reset and processing safely continues.
REFERENCES:
patent: 3898623 (1975-08-01), Cormier
patent: 4688221 (1987-08-01), Nakamura et al.
patent: 4797812 (1989-01-01), Kihara
patent: 4807112 (1989-02-01), Hamasaki
patent: 4920480 (1990-04-01), Murakami et al.
patent: 4930065 (1990-05-01), MeLagan et al.
patent: 4979096 (1990-12-01), Ueda et al.
patent: 4989113 (1991-01-01), Hull, Jr. et al.
patent: 4999769 (1991-03-01), Costes et al.
patent: 5027310 (1991-06-01), Dalrymple
patent: 5072374 (1991-12-01), Sexton et al.
patent: 5099417 (1992-03-01), Magar et al.
patent: 5131082 (1992-07-01), Bonevento et al.
Fleming Michael R.
Sheikh Ayaz R.
Sun Microsystems Inc.
LandOfFree
Method and apparatus for the prevention of race conditions durin does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method and apparatus for the prevention of race conditions durin, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method and apparatus for the prevention of race conditions durin will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1011920