| 摘要 |
PURPOSE:To decrease number of I/O ports by bringing an output signal whose active state is not overlapped in a normal sequence amount output signals of a microcomputer into a specific state in response to an input of an abnormity detection signal. CONSTITUTION:The microcomputer (CPU) 1 incorporates an ROM, an RAM, an I/O and a counter and outputs of comparators 2a-2d are fed to the CPU 1. Reference voltages Vref 1-4 are fed to inverting inputs of the comparators 2a-2d and a thermister input signal THin is fed to a non-inverting input. When a cassette paper feeding solenoid control signal (CPUSD) and a register solenoid control signal (RGSD) whose active states are not overlapped on a normal sequence are brought into logical 1 at the same time, outputs of drivers 4a, 4b in the CPU 1 are zero to inhibit the operation of a cassette paper feeding solenoid 9 and a register solenoid 10. Thus, number of I/O ports is reduced to detect various abnormity states. |
