AT89LP51 datasheet(43/113 Pages) ATMEL

부품명	AT89LP51

상세설명	8-bit Microcontroller with 4K/8K Bytes In-System Programmable Flash

PDF	113 Pages

Scroll/Zoom	100%

제조업체	ATMEL [ATMEL Corporation]

홈페이지	http://www.atmel.com

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43 / 113 page

3709C–MICRO–5/11

AT89LP51/52 - Preliminary

Figure 10-1. Quasi-bidirectional Output

Figure 10-2. Input Only

Figure 10-3. Input Circuit for P3.2, P3.3, P4.6 and P4.7

10.1.3

Open-drain Output

The open-drain output configuration turns off all pull-ups and only drives the pull-down transistor

of the port pin when the port latch contains a logic “0”. To be used as a logic output, a port con-

figured in this manner must have an external pull-up, typically a resistor tied to V

DD. The pull-

down for this mode is the same as for the quasi-bidirectional mode. The open-drain port configu-

ration is shown in Figure 10-4. The input circuitry of P3.2, P3.3, P4.6 and P4.7 is not disabled

during Power-down (see Figure 10-3) and therefore these pins should not be left floating during

Power-down when configured in this mode.

Figure 10-4. Open-Drain Output

1 Clock Delay

(D Flip-Flop)

Strong

Very

Weak

Port

VCC

From Port

Input

Data

PWD

Port

Input

Data

PWD

Port

Input

Data

Port

From Port

Input

Data

PWD

AT89LP51 데이터시트(PDF) 43 Page - ATMEL Corporation