PURPOSE: To achieve a testing of a function circuit without use of a special test terminal, by supplying a clock pulse for testing to an alarm terminal to reset a desired frequency dividing stage while a clock pulse is supplied to the function circuit.
CONSTITUTION: When testing a function circuit, first, an alarm terminal 6 normally set to '0' is set to '1' and then, a clock pulse is supplied thereto. When pulse from an output Q3 of a frequency dividing stage 3 does not fall with at the pulse state at 0, outputs Q and -Q of an FF circuit 7 are held at 1 and 0 respectively to generate an alarm signal from an alarm control circuit 5 while a clock pulse passes through a gage circuit 9. Then, a clock pulse passes through a gate circuit 10 to reset a frequency dividing stage 2 while passing through a gate circuit 11 to be supplied to the frequency dividing stage 3. Thus, a driving circuit 4 is tested, too.
JPS58154688A | 1983-09-14 | |||
JPS57201885A | 1982-12-10 |