Abstract: An automatic method of generating slits in power buses on a chip. The present invention includes three embodiments. The first embodiment is directed to a generic method of generating power slits. Once bus dimensions are identified, predetermined parameters for optimal power slit size and number are used to automatically generate a power slit layer for the mask database. The second embodiment is a continuation of the first embodiment and is directed to a method of generating power slits for an orthogonal corner case; where two buses overlap at 90.degree. angles. This is performed by locating all corner cases. Power slits are removed within a cross (corner/intersect) area of overlapping buses. At this point power slits from overlapping buses are extended across the corner/intersect area. The extension lines are logically ANDed together resulting in points within the corner/intersect area where the extension lines intersect.
Type:
Grant
Filed:
February 10, 1992
Date of Patent:
September 6, 1994
Assignee:
S-MOS Systems, Inc.
Inventors:
Chong M. Lin, Tatao Chuang, Tran Long, Hy Hoang
Abstract: The present invention provides a test and set bypass mechanism which allows access to a semaphore while eliminating memory bandwidth degradation due to the traditional "spin-locking" problem. Generally, a storage and comparison structure in a processor, such as a content addressable memory (CAM), is used to store the address of the semaphore whenever it is requested. Thus, the process/processor, or other processors in a multiprocessor system, then need only check to see if the semaphore address is present in its respective storage and comparison structure. Consequently, there is no need to make multiple memory transactions for failed access of the semaphore, and hence, effective memory bandwidth is increased.
Abstract: A high-speed, area efficient, low-power absolute value arithmetic unit that efficiently produces the absolute value of the difference of two input operands. This arithmetic unit is adaptable to provide other output functions. Further, the arithmetic unit of the present invention may be utilized as a data path element in a high performance floating point arithmetic unit. The present invention includes a propagate and generate block, a carry-chain-and a difference multiplexer. Operands A and B are received by the absolute value arithmetic unit. The propagate and generate block converts operands A and B into propagate signals and generate signals. The carry-chain-receives propagate and generate signals and produces carry-chain-propagate signals and carry-chain-generate signals for every bit, where the most significant carry-chain-generate signal is used to indicate a borrow.
Type:
Grant
Filed:
May 22, 1992
Date of Patent:
October 5, 1993
Assignee:
S-MOS Systems, Inc.
Inventors:
Jeffrey M. Dodson, Christopher T. Cheng
Abstract: A interleaved channeless gate array architecture for fabricating very large scale integration circuits created in a gate array comprises a plurality of rows or columns of basic cells wherein each of the cells includes a pair arrangement of complementary channel MOS transistors formed in adjacently disposed different conductivity type diffusion regions. A gate electrode structure for the basic cells comprises a pair of comb-shaped gate electrodes each having a plurality of parallel spatially disposed legs. Gate electrode pairs are formed over each of the basic cells in opposite opposed relation with their legs alternately interleaved relative to each other.