Ten Daily Electronic Common Sense-Section 132

What are the commonly used random access memories?

1. Static RAM (SRAM): The characteristic of static RAM is that it can reliably maintain the stored information. Refresh operation is not required, as long as the power supply is uninterrupted, the information will not be lost. However, compared with dynamic RAM, it consumes more power and is more expensive. It is often used in microcontroller application systems with small data storage capacity.
2. Dynamic RAM (DRAM): Dynamic RAM has the advantages of low power consumption and low cost. However, in order to ensure that the data information in the dynamic RAM is not lost, it needs to be refreshed continuously. Therefore, it is necessary to refresh the logic circuit, which makes the circuit more complicated. For these reasons, the application of dynamic RAM in microcontroller systems is limited. It is especially suitable for occasions requiring large-capacity data storage space.
3. Integrated RAM (iRAM): Integrated RAM is a DRAM with its own refresh logic circuit. It has the advantages of high integration, low power consumption, cheap price and simple interface.

What are the microprocessor units included?

The microprocessor unit includes digital memory (EEPROM, ROM, RAM), I/O interface, microprocessor, digital/analog converter (DAC) and so on.

What is the basic principle of DDS?

The basic principle of DDS is to use the Nyquist time domain sampling theorem to perform frequency synthesis in the time domain. The waveform is generated by the look-up table method, and the frequency and step of DDS are easy to control. And the synthesized frequency depends on the speed of the accumulator and the look-up table.

What is an embedded system?

According to the IEEE definition, an embedded system is “a device that controls, monitors, or assists the operation of equipment, machines, and workshops.”
According to the historical, essential and universal requirements. Embedded system should be defined as: “a special computer system embedded in the object system”.
By general definition, an embedded system is application-centric. Based on computer technology, adopt scalable software and hardware. It is suitable for special-purpose computer systems with strict requirements on function, reliability, cost, volume and power consumption.

What are the ISE series software series?

• ISE series software is divided into 4 series:
  1. WebPACK
  2. BaseX
  3. Foundation
  4. Aliance

According to the different sensitive membranes, what can ISE be divided into?

According to the different sensitive films, ISE can be divided into two categories: crystalline film electrodes and amorphous film electrodes.
Among them, crystalline membrane electrodes include single crystal membrane electrodes, polycrystalline membrane electrodes and heterogeneous membrane electrodes (precipitated membrane electrodes);
Amorphous membrane electrodes are further divided into rigid matrix electrodes (glass electrodes), liquid membrane electrodes, and ion-selective microelectrodes.

What does the security environment include?

1. SE identifier (SEID byte)
2. Component
3. Authentication of certificate holder
4. Access control
5. SE retrieval

Briefly describe the complete FPGA/CPLD design flow?

The complete FPGA/CPLD design process includes circuit design and input, functional simulation, synthesis, post-synthesis simulation, implementation, post-wiring simulation and verification, board-level simulation verification and debugging, and other major steps.

What are the common external storage for embedded systems?

Commonly used external storage in embedded systems are: Hard disk, NAND Flash, CF card, MMC and SD card, etc.

What is the general MFRC500 command?

1. The data stream that needs to be input in the command comes directly from the FIF0 buffer.
2. The number of parameters required in the command. Only when the correct amount is obtained from the FIF0 buffer can the execution of the command be initiated.
3. When the command starts, the content of the FIF0 register is not cleared. So you can write the command parameters and data to the FIFO buffer first, and then start the command.
4. Every command (except the Start Up command) can be interrupted by a new command written by the MCU into the command register.