| 摘要 |
PURPOSE:To prevent previously the burning of a dot printer due to a program runaway which is caused by a voltage fault, the destruction of a memory, etc., by keeping the dot printer under an ON state. CONSTITUTION:When the dot information is fed to an I/O interface 18 from a CPU10, the interface 18 latches a strobe signal of prescribed timing and at the same time delivers a dot output signal (A) to a driver 20. If a latch output is obtained at a time point t=t0, this output is applied to a time limiting circuit 24 in the form of a dot ON signal for triggering. The circuit 24 applies an output to the driver 20 as a gate signal (B) for a prescribed time T. The driver 20 supplies a dot output signal (A) existing within a dot ON enable time corresponding to the time T to a printer 22 in the form of a dot output (C). If a program runaway occurs due to a voltage fault, the destruction of a memory 14, no latching is carried out to the dot information at that time point by the strobe signal. Therefore, the circuit 24 is not actuated. |
