Toshiba TC9314F Manual page 58

Cmos digital integrated circuit silicon monolithic

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3. CPU Stop Function, STOP Flip-Flop Bit

The STOP flip-flop bit is set to "1" when the V

prevents CPU malfunction by shutting down the CPU. When a voltage of 1.5 V or less is applied to the V

pin, the program counter stops and instruction execution ceases in the CPU.

When a voltage higher than 1.5 V is again applied to the V

was shut down, the clock and other timings are no longer valid. Use the STOP flip-flop to test whether the

CPU stop function operated. Perform initialization or clock correction if required.

The STOP flip-flop bit is reset to "0" whenever the RESET port 2 Hz flip-flop is set to "1".

Note 63: After a system reset or execution of the CKSTP instruction, the timer port and the STOP flip-flop are

reset to "0".

Note 64: If the V

voltage falls below 1.5 V when clock-stop mode is set, the CKSTP instruction cannot be

executed. Be careful with the supply voltage timing, for example, when the radio is off.

Note 65: The key scan data immediately after restarting the CPU are undefined.

voltage applied to the CPU falls below 1.5 V. This

pin, the CPU starts up again. As the CPU

TC9314F

2003-07-03

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