Data capture in an uninterrupted counter
AssigneeHewlett-Packard Company
InventorsDavid C. Chu, Michael J. Ward
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Abstract
A method of sampling accurately the instantaneous content of a high speed counter without interrupting the counting process is provided. The method is applicable even when the higher order digits of the counter are constructed by slower switching circuits configured in either a synchronous or ripple-through arrangement. The switching and carry propagation times of these higher order counters need not be shorter than the time between successive events being counted. Sampling of the contents may be made repeatedly in the interim without affecting the totality of the final count.
Claims7
An N-bit counting apparatus comprising:
- an M-bit low-order synchronous counter;
- an (N-M)-bit high-order counter coupled to said synchronous counter in tandem;
- first storage means coupled to said synchronous counter for capturing the contents of said synchronous counter;
- second storage means coupled to said high-order counter for capturing the contents of said high-order counter;
- and
- delay means coupled to said second storage means to prevent capturing for a predetermined period in response to the most significant bit from said synchronous counter.
Dependencies are inferred from the claim text.