Circuit for Measuring Pulse Periods and Pulse Lengths
Original Publication Date: 1984-Dec-01
Included in the Prior Art Database: 2005-Feb-05
The illustrated circuit permits measuring deviations from nominal pulse period or pulse length values with high accuracy and resolution. During measuring, clock pulses are counted, and a first counter CTR1, used for that purpose, stores a number of pulses amounting to half its capacity C. A second counter CTR2 serves to count the wrap- around events of CTR1. The permissible pulse deviations are chosen to correspond to C/2, so that variations of + C/2 may be measured by the circuit. To cope with different pulse periods and pulse lengths, CTR1 is preset to a suitable value, and overflow pulses to be counted by CTR2 are derived from a suitable stage of CTR1. In the illustrated circuit, pulses are applied to an input stage INP supplying the appropriate start/stop counting signals S/S to a timing circuit TCT.