1
John R Obermeyer Jr, John F Shelton, Donald A Williamson: Apparatus for generation of scan control signals for initialization and diagnosis of circuitry in a computer. Hewlett Packard Company, Roland I Griffin, Alan H Haggard, October 2, 1990: US04961013 (22 worldwide citation)

A scan testable circuit in a computer system is controlled by using a single scan clock and a fixed delay circuit to realize the required scan clocks and a required scan mode enable signal. The multiple signals are generated from a subset of signals supplied to the scan control signal generation cir ...


2
Debendra Das Sharma, Donald A Williamson, Edward M Jacobs: Method and apparatus for preventing underflow and overflow across an asynchronous channel. Hewlett Packard Development Company, November 2, 2004: US06813275 (15 worldwide citation)

An apparatus and method for an improved asynchronous communication channel between a transmitter and a receiver having separate clocks. The invention provides a simple implementation that solves both the overflow and the underflow problem using the same mechanism, and reduces complexity by eliminati ...


3
Donald A Williamson, John F Shelton: Means for fast instruction decoding for a computer. Hewlett Packard Company, Edward Y Wong, January 6, 1987: US04635188 (10 worldwide citation)

A scheme for improving the decoding time of macroinstruction opcodes in a programmed computer is provided. By having a direct Instruction Jump Table responding to macroinstructions and a pipelined Address Jump Table responding to the same macroinstructions simultaneously, larger sequences of microin ...


4
Donald A Williamson, John A Wickeraad: Apparatus and method to align clocks for repeatable system testing. Hewlett Packard Development Company, May 22, 2007: US07221126 (5 worldwide citation)

A method and apparatus using a clock generator with sequential logic to align the phase of a first clock generated on a receiving integrated circuit (IC) chip to a second clock received by the receiving IC chip. One embodiment of the invention involves a method for aligning the phase of a first cloc ...


5
Debendra Das Sharma, Ashish Gupta, Donald A Williamson: Verification of asynchronous boundary behavior. Hewlett Packard Development Companay, July 22, 2003: US06598191 (5 worldwide citation)

A function for verifying an asynchronous boundary behavior of a digital system. The asynchronous boundary is formed at a coupling between a first series of registers clocked by a write clock (the write domain), and a second series of registers clocked by a read clock (the read domain). A delay regis ...