UPD17708 datasheet(152/356 Pages) NEC

No. de pieza	UPD17708

Descripción Electrónicos	4-BIT SINGLE-CHIP MICROCONTROLLERS WITH DEDICATED HARDWARE FOR DIGITAL TUNING SYSTEM

PDF	356 Pages

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Fabricante Electrónico	NEC [NEC]

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µPD17704, 17705, 17707, 17708, 17709

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13.2.3 Flip-flop and BTM0CY flag

The flip-flop is set at fixed intervals and its status is detected by the BTM0CY flag of the basic timer 0 carry

When the BTM0CY flag is read, it is reset to “0” (Read & Reset).

The BTM0CY flag is “0” at power-ON reset, and is “1” at CE reset and on execution of the clock stop

instruction. Therefore, this flag can be used to detect a power failure.

The BTM0CY flag is not set after power application until an instruction that reads it is executed. Once the

read instruction has been executed, the flag is set at fixed intervals.

Figure 13-4 shows the configuration of the basic timer 0 carry register.

Figure 13-4. Configuration of Basic Timer 0 Carry Register

Name

Flag symbol

Address

17H

Read/Write

R & Reset

Basic timer 0 carry

Power-ON reset

WDT&SP reset

CE reset

R: Retained

Clock stop

Flip-flop is not set

Flip-flop is set

Fixed to “0”

Detects status of flip-flop

000

UPD17708 Datasheet(PDF) 152 Page - NEC