TTY_RESETS_CPU

Published:2009/7/14 22:54:00 Author:Jessie | From:SeekIC

Circuit uses break key on TTY as reset button for microprocessor. Retrig-gerable mono IC1 monitors data input line from TTY, which goes low for spacing condition. During normal data input, constant spacing pulses in data retrigger mono, keeping IC2 reset. When break key is depressed, input data goes to steady space and IC1 times out. IC2 then transfers high on its data input to its output to produce reset signal for CPU. Values of R2 and C1 give 150-ms period for mono, suitable for baud rates of 110 and higher,-C. Sondgeroth, Reset Your CPU from Your TTY's Break Key, EDN Magazine, May 5, 1978, p 39.



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