Ten Daily Electronic Common Sense-Section 38

What is the performance of error detection?

• The transmitter can detect all local errors;
• It has a high error detection rate for the errors of the whole protocol.

What are the three types of semiconductor memory?

Read-only memory (MROM, EPROM), read-write memory (SRAM, DRAM), non-volatile read-write memory (NVRAM).

What are the basic components of a typical digital control system?

The basic components of a typical digital control system include microprocessors, programmable logic devices, analog input/output, switch input/output, memory chips, communication chips, etc., which mainly complete various control algorithms and related interfaces with other circuits.

What are the steps involved in the initialization process of the transmitter?

1. The ENSCI bit in the SCI control register SCCl is written to logic 1 to allow the SCI module function.
2. Write logic 1 to the TE bit in the SCI control register SCC2 to enable the SCI transmitter function.
3. Read the SCI status register SCSl first, and then write the data to SCDR.

Repeat step ③. The sending logic automatically sets the sending data register empty state flag SCTE and sending end state flag TC in SCSl.
The software can read these two flags at any time. When SCDR transmits a byte to the transmit shift register, the transmitter empty flag SCTE in SCSl is set to 1, indicating that SCDR can receive new data from the internal data bus at this time.
If the SCI transmit interrupt bit SCTIE in SCC2 is enabled, the SCTE flag will also generate a transmitter empty interrupt request. When the data is sent by the TxD pin through the shift register, the TC flag is set to 1.
If the SC1 transmission end interrupt bit TCIE in SCC2 has been enabled, the Tc flag will also generate a transmission completion interrupt request. When the transmitter shift register is not transmitting a character, the TxD pin goes into an idle state and assumes a high level.
If software clears the ENCl bit in SCCl, both the transmitter and receiver relinquish control of the E port pins.

What are the characteristics of the MCU control system?

1. Suitable for multi-variable control.
2. Suitable for data comparison and search control.
3. Suitable for counting control.
4. Suitable for real-time follow-up control.
5. It is easy to change the control mode.
6. Suitable for network control.

What is a fiber vortex flowmeter?

When a bluff body is placed in a fluid, under certain conditions regular vortices are created downstream of the fluid flow.

What are the important registers of the MSCAN module?

1. Module control register CMCRl LOOPB – loopback self-test mode: LOOPB=1, start the loopback self-test, the bit stream output by the MSCAN transmitting device is all echoed back to its own receiving device, this mode can be used to detect whether the module is working normally; LOOPB =0, let MSCAN work normally. WUPM——Wake-up mode: WUPM=1, start the internal low-pass filter to avoid the parasitic signal on the bus to wake up the CPU; WUPM=0, once the bus signal jumps from 1 to 0, MSCAN wakes up the CPU. CLKSRC——Clock source: CLKSRC=1, select the output of CGM in AZ60A as the clock source of MSCAN; CLKSRC=0, select 2 frequency division of the off-chip oscillator as the clock source of MSCAN.
2. The address of the receiver flag register CRFLG CRFLG is $0504, and its 0th bit RXF is the “buffer full” flag. RXF = 1, which means that the foreground Rx cache is full, and the CPU can access the data in it. RXF=0, indicating that no new data is received.
3. The receiver interrupt enable register CRIER CRIER address is $0505, and its 0th bit RXFIE is the “receiver full” interrupt enable bit. RXFIE=1, indicating that a receive interrupt will be generated after receiving a message correctly; RXFIE=0, indicating that a receive interrupt is not allowed.
4. Transmitter flag registers CTFLGTXE2~TXE0——Tx buffer is empty: TXE2~TXE0 =1, the corresponding Tx buffer is free and can be used by the CPU to send new messages; TXE2~TXE0=0, the message to be sent has been in the corresponding Tx buffer. Ready.
5. Transmitter Control Register CTCRTXEIE2~TXEIE0——”Transmitter Empty” Interrupt Enable: TXEIE2~TXEIE0=1, when the corresponding Tx buffer is free, an interrupt is generated; TXEIE2~TXEIE0=0, “Transmitter Empty” interrupt is not allowed.
6. Configuration Register CONFIG2 The 0th and 4th bits in the CONFIG2 register of the AZ60A are directly connected to the MSCAN application. Bit 0 AZxx——AZ series enable bit: AZxx=1, the microcontroller is set to the organizational structure of the AZ series, the system includes MSCAN; AZxx=0, the microcontroller is set to the organizational structure of the AS series, the system does not include MSCAN. The fourth MSCAND – MSCAN disable bit: MSCAND=1, prohibit MSCAN from working; MSCAND=0, allow MSCAN to work.
7. MSCAN module initialization MSCAN initialization work includes the following parts:
   • In CONFIG2, select the microcontroller as AZ series and allow MSCAN to work.
   • Set the basic working mode of MSCAN in CMCR0 and CMCR1.
   • Select the method of MSCAN filtering identifiers in CIDAC, and set the acceptance code and mask bit in CIDAR0~CIDAR3 and CIDMR0~CIDMR3 respectively.
   • Set the bit timing logic of MSCAN in CBTR0 and CBTR1 to determine the communication bit rate.
   • In CRIER and CTCR, set the relevant interrupt to allow occurrence.
   • Start the MSCAN module.

What are the advantages of the NPort serial switch?

As a conversion device between serial port and network port, the NPort serial switch is also a Web server. The device is connected to the switch through a network cable, and then connected to the host or the Internet, which enables the monitoring host to view the serial switch through a Web browser (such as Microsoft Internet Explorer). status, and the parameter status of each serial port.

What are the command registers of SJAl000?

• Bus timing register
• Output control register
• Clock frequency divider register

What are the functions and characteristics of transient voltage suppression diodes?

• Features and applications: Transient Voltage Suppressor (TVS) is a new type of overvoltage protection device developed on the basis of Zener diode technology. When the transient voltage suppression diode is subjected to transient high voltage (such as surge voltage, lightning interference, and peak voltage), it can quickly reverse breakdown, change from a high resistance state to a low resistance state, and clamp the two-r two-disturbance pulse. Bit -j two specified value, so as to ensure that electronic equipment or components are not damaged. The clamping time is defined as the time required to reach the minimum reverse breakdown voltage from zero volts. The clamping time of the TVS diode is extremely short, only Ins, and the transient pulse peak current that can withstand is as high as tens to hundreds of amps. Its performance is better than varistor (VSR), and the consistency of parameters is good. Therefore, TVS_J’ is used as an overvoltage protector in various instruments, meters, white control devices and household appliances, and can also be used to protect monolithic switching power supply integrated circuits, MOS power devices and other voltage-sensitive semiconductor devices.
• Category: TVS diodes can be divided into four categories according to their peak pulse power, namely 500W, 1000W, 1500W, 5000W. Each type is divided into several types according to its nominal voltage, the minimum breakdown voltage is 8.2V, and the maximum is 200V. There are two types of transient voltage suppression diodes: unidirectional transient voltage suppression diodes and bidirectional transient voltage suppression diodes.