Abstract: The present invention provides a method and system for providing observability of memory address access for self-timed cache designs. A system according to the present invention for determining which memory location has been accessed in a self-timed cache comprises a content addressable memory; a secondary memory coupled to the content addressable memory, wherein the secondary memory includes at least one memory location which may be selected by the content addressable memory based upon a self-timed cache access. The system further includes a test circuitry coupled to the content addressable memory, wherein the test circuitry stores a pointer which points to a selected memory location in response to the self-timed cache access of the secondary memory.

Abstract: An exclusive OR circuit (10) includes an input stage (11) and a control arrangement (12,13) for controlling an exclusive OR logical evaluation. The control arrangement includes a pre-charge stage (12) which responds to a first level clock signal to enable the desired exclusive OR logical evaluation. The input stage (11) is connected to receive a first input signal and a second input signal and is also connected to an evaluation node (23). When the logic state of one input signal is unequal to the logic state of the other input signal, the input stage (11) couples the evaluation node (23) to ground. An output stage (13) of the control arrangement inverts the signal at an internal node (24) to produce the output from the exclusive OR circuit. A pre-charge stage (12) couples the internal node (24) to the evaluation node (23) only in response to a "high" clock signal.

Abstract: A voltage converter circuit (10) includes a primary P-type FET (20) having its source-drain conduction path connected between an input (22) and a first output node (23). An N-type FET (21) is connected in parallel with the primary P-type device (20) between the input (22) and first output node (23). The gate electrode of the primary P-type device (20) is connected to the first output node (23) while the gate electrode of the N-type device (21) is connected to a second voltage supply at the voltage level of a desired second voltage signal. A first digital signal at a first voltage level is applied to the input (22). The voltage produced at the first output node (23) equals the desired second voltage level and comprises the input signal voltage reduced by the threshold voltage of the primary P-type device (20). One or more additional P-type devices (40) may be connected in series with the primary P-type device (20) to reduce the output voltage level further.