超星 - 第七章作业--单片机与开关键盘以及显示接口 - 查题吧

单选题

In SCM application system, LED digital tube display circuit usually has () display mode.

A. Static
B. News
C. Static and dynamic
D. Inquiry

单选题

The segment code of the character "6" is () when the common anode LED digital tube is driven by reverser.

A. 06H
B. 7DH
C. 82H
D. FAH

单选题

If LED digital tube adopts dynamic display mode, the following statement is wrong.

A. Connect the segments of the digital tubes in parallel
B. The segment selection is controlled by an 8-bit I / O port
Connect the common end of each digital tube directly to + 5V or GND
D. The bit selection of each digital tube is controlled by its own independent I / O port

单选题

The structure of the key switch is usually a mechanical elastic element. When the key is pressed and opened, the contact will be unstable at the moment of closing and opening. In order to eliminate the adverse consequences caused by jitter, the methods often used are () .

A. Hardware de-bouncing(去抖动)
B. Software de-bouncing
C. , hardware and software two methods
D. Mono-stable circuit(单稳态电路) de-bouncing method

单选题

The segment code of the character "6" is () when the common anode LED digital tube is driven by inverter.

A. 06H
B. 7DH
C. 82H
D. FAH

单选题

The seven segment Common cathode LED displays the character "H", and the segment code should be ()

A. 67H
B. 6EH
C. 91H
D. 76H

判断题

When. P0 port is used as bus port, it is a bidirectional port.

A. 对
B. 错

判断题

The font code of LED digital tube is fixed.

A. 对
B. 错

判断题

When. P0 port is used as general I / O port, the external pin must be connected with pull-up resistor, so it is a quasi -bidirectional port.

A. 对
B. 错

判断题

When P1-P3 ports are used as input ports, 1 must be written to the port register first.

A. 对
B. 错

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