Ten Daily Electronic Common Sense-Section 139

What are the advantages of KMV power control?

1. Reduce costs.
2. Improve business continuity.
3. Not limited to hardware platform and operating system.

What is an atomic switch?

The so-called atomic switch (atomic switch) is that there is a very small gap (nanoscale) in the device, through the corresponding electrical operation. The “conductive channel” that can change the resistance state is connected or disconnected in the middle of this extremely small gap, so as to realize the change of resistance state.
Aono’s research group used the redox reaction of the active metal silver (Ag) in an electric field to achieve the growth and breaking of metallic conductive bridges in extremely small spaces, the work was published in the journal Nature.
A very thin layer of silver is sandwiched between the lower electrode silver sulfide and the upper electrode platinum. At this time, the upper and lower electrodes are in a low resistance state due to the connection of metallic silver. In the process of electrical operation, a forward voltage is applied between the upper electrode platinum and the lower electrode silver sulfide to form an electric field from platinum to silver sulfide.
When the electric field is strong enough, the thin layer of silver between the upper and lower electrodes oxidizes. The original silver atoms are oxidized to silver ions and migrate towards the direction of silver sulfide driven by the electric field. Because the lower electrode is silver sulfide, oxidized silver ions can enter the lower electrode structure so that a thin layer of air appears in the place of the original silver thin layer. At this time, the upper and lower electrodes are no longer connected, and the device is in a state of high resistance.
When the direction of the electric field is changed, the oxidized silver ions will move to the upper electrode driven by the electric field and undergo a reduction reaction. It is worth noting that the distance between the two electrodes is very small.
The phenomenon of quantum conductance occurs when reduced silver ions approach the two electrodes to be connected. Devices of this type are collectively referred to as atomic switches. Such devices usually use the above-mentioned metal redox reaction and electromigration to form a conductive bridge to complete the transition between high and low resistance states, and the size of the conductive bridge is required to be very small (nanoscale). The key to fabricating such devices lies in how to form extremely small electrode gaps. The acquisition of this quantum conductance allows us to gain a deeper understanding of the resistance transition mechanism of the redox and electromigration type resistance transition memory devices based on this active electrode.

What are the advantages of using VHDL for engineering design?

• Compared with other hardware description languages, VHDL has stronger behavior description ability, which determines that it becomes the best hardware description language in the field of system design. The powerful behavior description ability is an important guarantee for describing and designing large-scale electronic systems from the logic behavior without specific device structures.
• VHDL’s rich simulation statements and library functions enable the functional feasibility of the design system to be checked in the early stage of any large-scale system design. Designs can be simulated at any time.
• The behavior description ability and program structure of VHDL statement determine that it has the function of supporting the decomposition of large-scale design and the reuse of existing design. A large-scale system that meets market demand can efficiently and quickly complete tasks that can only be achieved by multiple people or even multiple generation teams working in parallel.
• For a certain design completed with VHDL, EDA tools can be used for logic synthesis and optimization, and the VHDL description design can be automatically transformed into a gate-level netlist.
• VHDL is relatively independent in describing the design, and the designer may not understand the structure of the hardware. There is also no need to manage what the target device is for the final design implementation, but to design independently.

What does the Helmholtz model need to pay attention to?

1. The opposite happens on the other electrode.
2. Sand is a part of coffee, determined only by electric charge.

What are the measurement methods for tag antenna impedance?

Mirror method to measure the balun test method to measure the line method to sweep the long line method.

What are the characteristics of electrolytic capacitors?

1. The shell color of electrolytic capacitors is usually blue. In addition, there are black, etc., and its shape is usually cylindrical.
2. It has two pins. In a polarized electrolytic capacitor, these two pins are divided into positive and negative poles, and the position of the negative pole pin will be marked with a “one” symbol on the shell.
3. In a non-polar electrolytic capacitor, its two pins are not divided into positive and negative poles, and there is no symbol indicating polarity. According to this feature, it can be distinguished whether it is a polar or non-polar electrolytic capacitor.
4. The capacity of electrolytic capacitors is generally large, above 1uF (the capacity of some imported electrolytic capacitors is less than this value), and the direct marking method is adopted.
5. SMD electrolytic capacitors have no long leads.

What are the ways to describe the design of the Verilog HDL program?

1. Structure description method;
2. Behavior description method;
3. Data flow description method.

What is the basic operation of UARTn?

1. Set the I/O connection to UART;
2. Set the serial port baud rate (UnDLM and UnDLL);
3. Set the serial port working mode (UnLCR and UnFCR);
4. Send or receive data (UnTHR and UnRBR) ;
5. Check the serial port status word or wait for the serial port interrupt (UnLSR).

Utility difference and forwarding set are utility continuous functions, so what method is used to describe the function in the TOUR algorithm implementation?

Discrete sampling

What principles should IP core design follow?

1. Standardization. Designed in strict accordance with the specifications, the system is upgradable, inheritable and easy to system integration.
2. Simplicity. The simpler the system design, the easier it is to analyze, verify, and achieve timing closure.
3. Localization. Localization of problems in timing and verification makes it easier to find and fix problems, reducing development time and improving quality.