Ten Daily Electronic Common Sense-Section 12

When did you enter the exception mode?

1. After entering the management mode after the processor reset, the operating system kernel is usually in the management mode.
2. When the processor fails to access the memory, enters the data access suspension mode.
3. Enters undefined mode when the processor encounters an unsupported instruction.
4. The interrupt mode and the fast interrupt mode respond to two different levels of interrupts of the ARM processor respectively.

What are the detections of the vane air flow sensor?

The detection methods of the vane air flow sensor mainly include open circuit detection and on-road detection.·

Open circuit detection mainly detects the internal condition of the sensor when the sensor and the line are not connected.

It is generally judged by detecting the resistance value or the on-off condition between the terminals.

What are the operating modes of ModelSim?

• User graphical interface (GUI) mode.
• Interactive command line (Cmd) mode.
• Tcl and macro mode; batch mode.

How to receive serial peripheral interface in DMA mode?

①Use the SMOD and TAGD bits to configure the serial peripheral interface into DMA mode;
②DMA mode configuration is successful;
③The serial peripheral interface receives one byte of data from the target device;
④Serial peripheral interface requests DMA service;
⑤DMA receives data from the serial peripheral interface;
⑥Write data OxFF to SPTDATn automatically;
⑦ Return to step ④ until the DMA count becomes 0;
⑧ Set the SMOD bit to configure the serial peripheral interface into interrupt or polling mode, and clear the TAGD bit;
⑨ If the ready flag bit of SPSTAn is set, read the last byte of data.

What great changes have the embedded industry experienced in recent years?

1. The product market window is now expected to double in a period of 6 to 9 months;
2. The opportunity to redefine the global market and the expanding application space;
3. The Internet is now a demand rather than an auxiliary means, Including the adoption of wired technology and the emerging wireless technology;
4. Electronic-based products are more complex;
5. Interconnected embedded systems can generate new applications that rely on network infrastructure;
6. The processing power of microprocessors The rate predicted by Moore’s Law is increasing. The law states that the number of integrated circuits and transistors doubles every 18 months.

What are the characteristics of the UART interface circuit?

Multi-channel UART interface (up to 8 channels); fast bus cycle time; large FIFo memory depth (up to 256 bytes); high-speed UART baud rate (up to 5 Mbit/s); advanced interrupt function.

What are the conditions for a lock-in amplifier that meets various measurement requirements?

1. Very low MDS, probably below the order of 10-4FS.
2. Very high overload level, plus bandpass amplifier to achieve dynamic reserve of 105.
3. A very wide total dynamic range of up to 108.
4. Dynamic coordination can be controlled to optimize measurements under any given conditions.

What is a pyroelectric sensor?

A pyroelectric sensor is a device that converts a change in temperature into a change in electrical quantity.

What is the reason for the wireless system to adopt the PWM scheme?

The reason why the wireless system uses the PWM scheme is because the switching frequency generated by the oscillator is fixed, and the spectrum of the noise is formed on the basis of this fixed frequency.

What are the applications of unidirectional thyristors?

Unidirectional thyristor has the advantages of good control performance, fast response, small size and high efficiency, and is often used in rectifiers, non-contact switches and frequency conversion circuits.
The one-way thyristor is used in the dimming circuit of the desk lamp. The 220v alternating current is rectified into a pulsating voltage by the bridge type, and is charged to C2 after being adjusted by PR. When the voltage on C2 exceeds the trigger voltage of the thyristor gate, the thyristor is turned on.
When the pulse voltage is not enough to keep the thyristor turned on and cut off, the next pulse voltage will repeat the previous face to the barnyard.