Sun Microsystems, Inc.

Christopher Furman

Kevin B Normoyle

Deviprasad Malladi

Renukanthan Raman

Sharath Raghava

An apparatus for enhancing the speed of a synchronous bus includes a two register based FIFO with software control bits and a second clock signal. According to the invention, the second clock signal rd_clk is supplied by the same PLL that provides the main clock signal lg_clk. According to the invention, data is taken from the two registers in alternative clock cycles so that each of the register holds valid data for two clock cycles. A first software data bit is used to determine which of the two registers is unloaded first. Using the method and structure of the invention, the window for transferring valid data is increased and therefore the system employing the method and apparatus of the invention is more skew tolerant.

Method and apparatus for enhancing the speed of a synchronous bus

A method for performing electrical acceptance tests on a sub-system including a test substrate, a microprocessor and one or more associated computer components, such as SRAM, DRAM and ROM. A pin grid array, ball grid array, line grid array or equivalent test connector system is provided that allows direct addressing of selected circuits of the microprocessor and of each associated component. The microprocessor plus substrate are first tested together. If this test is successful, the associated components are then added, preferably one at a time, and the new sub-system is tested. If a particular sub-system fails a test, the cause(s) of failure can be isolated and removed, where possible, and the modified sub-system can be retested.

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Gilroy, CA, United States of America

Christopher Furman