Archive 06/24/2022

Sensing Design Challenge Solutions for Automotive Electronics

Consumer car buying habits are changing, which is also driving the growth of the automotive electronics industry. Automakers are adding more new or enhanced Electronic components to passenger vehicles each year, with body electronics currently growing at four times the rate of vehicle production.

Consumer car buying habits are changing, which is also driving the growth of the automotive electronics industry. Automakers are adding more new or enhanced electronic components to passenger vehicles each year, with body electronics currently growing at four times the rate of vehicle production.

Some of the current trends in new or enhanced functions are the addition of more complex electronic components in order to improve brand reputation and competitive differentiation, while making consumers safer and more comfortable. For example a hybrid electric car is like putting an iPod? Connecting to car entertainment systems has now become a fashion. Consumers also see Bluetooth connectivity between cell phones and integrated speakerphone devices as standard.

Complications

These features are just the tip of the iceberg. Other well-designed complex features that are not seen or touched by passengers, but affect their driving experience, are gradually being introduced into car design. Sensing lighting systems, multi-axis adjustable seats, intelligent weather control systems, collision avoidance systems and power cruise control have become extremely important in the 21st century automotive market. Consumers even expect high-quality dashboard features from automakers. Bringing these advanced capabilities into automotive systems often comes at a price.

One of the challenges for automotive electronics designers is to rapidly introduce new electronic components that improve passenger comfort, safety protection and other enhancements. Designers must reduce overall design and certification time and enhance existing system functionality without compromising increasingly stringent quality and reliability requirements and cost goals. To overcome these challenges, automotive electronics designers need more integrated solutions to increase the functional density of the system. High-function integration of mixed-signal components is an attractive alternative.

Capture, compute and communicate

new design challenges

Fuel tank sensing is a good example of the challenges faced by automotive electronics designers. Only a few years ago, fuel level sensors were a fairly straightforward design issue. It consists of a simple float device with scanning carbon brushes contacting a resistive surface, which causes the analog output Voltage to be proportional to the amount of oil remaining in the tank. But with today’s cars, tank design typically has to wait until near the end of the platform design, and most likely uses any unused space. This can result in an oddly shaped tank and a capacity no longer proportional to the liquid level, which complicates the design of the pontoon system. More importantly, the advent of alternative fuels and fuel derivatives has made the fuel composition of the tank important. For example, the ratio of gasoline to ethanol fuel affects engine dynamics such as ignition, burn time and exhaust emissions. Manufacturers now believe that a new generation of fuel tank sensors must be able to determine fuel composition, while providing this information to the car’s other electronic control systems. This has turned what was once considered a simple sensing design into a complex analytical control challenge.

It is worth noting that almost all systems in the car are being expanded. Active dew-point controllers are replacing windshield defogging, which avoids or eliminates the conditions needed for water droplets to condense. The rain-sensing wiper system integrates motor control and rain-sensing functions into one system. The closing of next-generation anti-pinch windows and sunroofs is another representative application where the microelectronic components of these safety systems need to be integrated.

The first generation of anti-pinch technology

The first generation of anti-pinch designs typically consisted of a mechanical drive system powered by an electric motor. The motor current is monitored by a controller and then compared to a fixed threshold representing a stall condition (where the motor is blocked from turning); as soon as this threshold is reached, the direction of the window is reversed from up to down. This system is shown in Figure 1.

  Sensing Design Challenge Solutions for Automotive Electronics

Figure 1: Control diagram of the first-generation anti-pinch window lift system

The first-generation design had several shortcomings. The first is to develop a method to distinguish the motor stall current when the motor is started and when the window is blocked (Figures 2 and 3). To meet this requirement, a fixed delay is added to the comparator circuit to ensure that it only starts comparing the stall current threshold after the motor has turned, although this sometimes fails to provide anti-pinch protection for a half-open window. For example, if the starting position of the window is only 10mm from the top, then the window is likely to hit the hard-stop before the critical timer expires.

Sensing Design Challenge Solutions for Automotive Electronics

Figure 2: Current Variation with Closed Window

Sensing Design Challenge Solutions for Automotive Electronics

Figure 3: Current Variation When Closing the Windows Meets Obstruction

The second disadvantage is that the parameters of the mechanical system can change over time, which can affect the working load of the motor, making the anti-pinch threshold larger or smaller.

Finally, these systems cannot adapt to changes in the driving environment due to the use of fixed thresholds. Thermal expansion effects of window weatherstrips can have a large effect on workload due to temperature changes. The force required to close the sunroof when the car is stationary is very different from that of a moving vehicle, and the force required to raise the window on a smooth road is also different from when the vehicle is driving on a rocky road. In both cases, the inability to compensate for these changes can affect safety or cause the windows to not operate properly.

Designers have tackled these three important challenges in different ways in the past. In some cases, they will add more sensors or use more precise control materials and components to alleviate these problems, but these approaches increase the cost and complexity of the design. This makes them increasingly need a low-cost anti-pinch function design to overcome these shortcomings.

new design solutions

As shown in Figure 4, a mixed-signal microcontroller containing a high-speed central processing unit (CPU) and a high-performance analog-to-digital converter (ie, bandwidth greater than 180 MSPS and resolution greater than 12 bits) is the best solution to this problem .

Sensing Design Challenge Solutions for Automotive Electronics

Figure 4: Anti-pinch system using a mixed-signal microcontroller

This approach allows designers to use a microcontroller to perform both the communication functions of the motor and the monitoring of the motor current. Communication noise can be detected directly by the on-chip analog-to-digital converter on the current sensor (ie, the shunt resistor) in the motor power circuit. This method can more accurately distinguish whether the motor is running or stalled, not only does the comparator circuit not need to add a fixed delay time, but also provides a complete anti-pinch function even when the window is half-open.

As shown in Figure 5, the system sets a variable motor current threshold based on historical data and parameter calculations to dynamically respond to motor load changes and limit system torque to an appropriate range, while limiting long-term factors such as motor wear and seals material aging) and short-term factors such as environment, humidity, temperature and vibration are taken into account. In addition, the system can exchange information with other electronic control units (ECUs), and use information such as outside temperature and vehicle speed as weighted inputs to determine appropriate thresholds (see Figure 6). Utilizing other systems not only improves overall system performance, but also avoids the additional cost of duplicating sensors on the vehicle.

Sensing Design Challenge Solutions for Automotive Electronics

Figure 5: Current variation during window closing with variable thresholds

Sensing Design Challenge Solutions for Automotive Electronics

Figure 6: Environmental parameters and historical data stored in in-memory tables that can be used to determine critical values

growth market

Automotive applications account for one-third of 8-bit microcontroller sales, and not only has the market size exceeded $3 billion, but it is also growing at a rate of nearly 10% per year. Automotive embedded system designers must develop more reliable, lower cost and more integrated solutions, so they need the most advanced microelectronic building blocks at their disposal. Mixed-signal microcontrollers with powerful analog and digital performance are the most cost-effective solution for these next-generation automotive electronics applications.

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Adaptive Load Regulation and Dynamic Power Control for Efficient Thermal Design of Analog Outputs

A typical programmable logic controller (PLC) today contains many analog and digital outputs used to control and monitor industrial and production processes. Modularity is widely adopted, and in terms of input and output (I/O), it covers the basic functions of analog I/O and digital I/O. Analog outputs present a special challenge (shown in Figure 1) because of the need to provide high-accuracy active drive setpoints over many different load conditions. The active driver stage becomes particularly important here; losses should be kept as small as possible.

Jürgen Schemel, Field Application Engineer

A typical programmable logic controller (PLC) today contains many analog and digital outputs used to control and monitor industrial and production processes. Modularity is widely adopted, and in terms of input and output (I/O), it covers the basic functions of analog I/O and digital I/O. Analog outputs present a special challenge (shown in Figure 1) because of the need to provide high-accuracy active drive setpoints over many different load conditions. The active driver stage becomes particularly important here; losses should be kept as small as possible.

The factors to consider are as follows:

• connected loads
• Maximum allowable ambient temperature and internal module temperature
• Number of channels and module size
• Electrically isolated interface
• Accuracy

In process automation, it is also often necessary to establish electrical isolation between the individual output channels. In addition to this, there are other requirements such as channel-based diagnostics or support for HART® signals. Robustness and fault tolerance are also prerequisites.

Adaptive Load Regulation and Dynamic Power Control for Efficient Thermal Design of Analog Outputs
Figure 1. Block diagram of an isolated analog output system.

Due to the development of semiconductors and the continuous improvement of mixed-signal technology, ultra-small circuits with high integration density are possible. The functionality of the analog output channels can be fully integrated into the IC. Therefore, the AD5758 integrates the basic functions of a DAC and driver, as well as numerous other analog and logic functions, such as ADC for diagnostics, intelligent power management, Voltage reference, protection against reverse and overshoot, in a 5 mm × 5 mm package size A high-voltage fault switch, a data calibration register, and an SPI communication interface.

The AD5758 (Figure 2) covers all common output ranges used in automation: unipolar 0 V to 10 V/0 mA to 20 mA, bipolar ±10 V/±20 mA, and all subranges (e.g. for 4 mA to 20 mA for process automation). Each setting provides a 20% overrange range. These values ​​are output in 16-bit resolution.

Adaptive Load Regulation and Dynamic Power Control for Efficient Thermal Design of Analog Outputs
Figure 2. Functional block diagram of the AD5758.

Power loss is greatly reduced

What properties make the AD5758 particularly suitable for temperature and space constrained applications? Losses mainly occur in the power supply section with the DC-DC converter and output driver stage. This is where intelligent power management comes in. The AD5758 features adaptive load regulation or dynamic power control (DPC). The DPC is activated in current output mode and controls the voltage on the driver stage required to drive a specific load. Depending on the operating conditions, the load voltage (I × RLOAD) of the current output is only a small fraction of the supply voltage. The supply voltage difference has to be dissipated in the form of power losses beforehand through the series transistors. The DPC now regulates the driver voltage to a few volts above the actual desired load voltage (leaving headroom for the output transistors) to minimize losses. Effective voltage regulation in this way is only possible with a switching regulator, which is already integrated in the AD5758 and automatically controlled according to the load. Even with the additional losses in the switching regulator and upstream power supply, the reduction in overall power loss is still significant, especially for small load resistances (see Table 1). This enables small form factor designs in the first place, and the board also maintains good heat dissipation.

Table 1. Theoretical losses at output current I = 20 mA and fixed supply voltage of 24 V (disregarding DC-DC internal power dissipation and efficiency)

RLOAD

VLOAD (V)

Loss without DPC (mW)

Loss with DPC (mW)

Decrease (mW)

0

480

100

380

50Ω

1

460

80

380

1 kΩ

20

80

50

30

Derating sets strict limits

Derating is defined as a reduction in performance under specified boundary conditions, similar to the safe operating area (SOA) in power semiconductors. Output modules that do not employ DPC are subject to tighter thermal constraints due to the aforementioned power losses and associated cooling issues. Today, it is common to have two or four channels on a credit card-sized module. Modules are typically rated for an ambient temperature of up to 60°C. However, under these ambient conditions, not all four channels can drive very small loads, because in the four channels without DPC, the power loss in the module can reach 3 W, and the heat generated can quickly make the components reach its limit value. With thermal derating (Figure 3), module manufacturers can use only one or two of the four available channels at higher ambient temperatures, greatly reducing availability and channel cost performance.

Adaptive Load Regulation and Dynamic Power Control for Efficient Thermal Design of Analog Outputs
Figure 3. Typical derating curve.

Because of the AD5758’s adaptive regulation, its power loss depends only on the load resistance to a small extent, and remains consistently below 250 mW for loads from 0 kΩ to 1 kΩ (Table 2). Therefore, depending on the design of the output module, eight isolated channels will be achieved with an overall power loss JA of 46 K/W and a temperature rise of less than 10°C at a power loss of 200 mW. The AD5758 is rated for ambient temperatures up to 115°C. This provides a lot of headroom for multi-channel modules without derating.

Table 2. Power measurements in DPC operating mode at I = 20 mA and power supply = 24 V

RLOAD

RLOAD

Load Voltage
(V)

load voltage
(V)

PTOTAL
(mW)

PTOTAL
(mW)

PLOAD
(mW)

PLOAD
(mW)

Power Loss
(mW)

Power loss
(mW)

0

0

222

222

0

0

222

222

250Ω

250Ω

5

5

296

296

100

100

196

196

750Ω

750Ω

15

15

509

509

300

300

209

209

1 kΩ

1 kΩ

20

20

609

609

400

400

209

209

The power dissipation value also includes the power dissipation due to the use of the ADP1031 for power and data isolation.

Power optimization

Supply voltages have different requirements:

• Logic voltage: In addition to the driver supply (operating mode depends on unipolar or bipolar), the AD5758 output IC requires a 3.3 V logic voltage to power the internal modules. This can be generated using an on-chip LDO regulator; however, to improve efficiency and reduce power loss, a switching regulator is recommended.

• Isolated drive power supply: For safety reasons, electrical isolation is always maintained between the PLC bus and I/O modules. Figure 1 shows this isolation in different colors, including three different potentials for the logic (bus) side, power supply, and field side outputs.

The isolation, power and output drivers are integrated into a single chip because the three parts are also typically spatially separated on the board, i.e. the outputs are located towards the front connector terminals and the backplane bus (as the name implies) is on the back Not wise.

The power management unit ADP1031 (Figure 4) performs all functions, and works in conjunction with the AD5758, enabling the development of isolated output modules with reduced space requirements and power loss (Figure 5).

Adaptive Load Regulation and Dynamic Power Control for Efficient Thermal Design of Analog Outputs
Figure 4. Power management unit ADP1031.

The ADP1031 integrates four modules in a 9 mm × 7 mm package size:

• Flyback converter to generate positive isolated supply voltage VPOS.
• Inverter to generate the negative supply VNEG required for bipolar output.
• A step-down converter to provide VLOG for the logic circuit of the AD5758.
• Isolated SPI data interface with additional GPIO.

The advantage of a flyback converter is high efficiency; only a small 1:1 transformer is required. The flyback converter can generate isolated driver voltages up to 28 V in the first stage. This creates an Inverter and a buck converter that share the same ground potential.

In the design process of the power management unit, ADI Company specially strengthened Electromagnetic Compatibility (EMC) and Robustness. For example, the output voltage is phase shifted, and the slew rate of the flyback controller is adjustable. Soft-start, overvoltage protection, and current limit functions have also been added for all three voltages for good measurements.

The isolated SPI interface is based on proven iCoupler® technology and transmits all control signals required for operation. A distinction is thus achieved between the high-speed data path (four lanes) and the lower-rate GPIO control path (three multiplexed lanes). Potential applications are the simultaneous activation of a multi-channel module or outputs in multiple modules via a common control signal, readback of error flags or triggering of a safe shutdown.

System advantage

The combination of the AD5758 and ADP1031 provides the full functionality of an isolated analog output with only two chips. Measuring approximately 13 mm × 25 mm, the aisle space requirement is smaller, half that of current solutions.

In addition to saving space, the integration of key functions results in a cleaner layout, easier separation of potentials, and a significant reduction in hardware costs. Analog Devices’ 8-channel demo design uses only a six-layer board, measuring 77 mm × 86 mm (Figure 6).

Summary of advantages:

• Smaller modules and more channels per module through power loss optimization
• No derating required, allowing higher ambient temperature
• Reduced hardware effort, thus lowering costs
• Easy scalability of multi-channel modules
• Robust design and more diagnostics

Adaptive Load Regulation and Dynamic Power Control for Efficient Thermal Design of Analog Outputs
Figure 5. Implementing a complete 4-channel analog output using the ADP1031 and AD5758.

Adaptive Load Regulation and Dynamic Power Control for Efficient Thermal Design of Analog Outputs
Figure 6. Isolated 8-channel AO module.

About the Author

Jürgen Schemel is currently a Field Applications Engineer at Analog Devices, supporting industrial strategic customers in automation, Industry 4.0 and condition monitoring applications. He received his master’s degree from the Offenburg University of Applied Sciences in 1996. He started his career at Siemens in the design of communication technology systems for industrial applications. Contact information:[email protected]

"A typical programmable logic controller (PLC) today contains many ana…

How does the subway screen door ensure the stability of communication?

With the rapid development of my country’s economy, the construction of subway engineering projects is also in the process of rapid development and continuous improvement. As the preferred mode of transportation for people, the comfort and convenience of the subway has attracted more and more attention, and safe and reliable operation is particularly important.

With the rapid development of my country’s economy, the construction of subway engineering projects is also in the process of rapid development and continuous improvement. As the preferred mode of transportation for people, the comfort and convenience of the subway has attracted more and more attention, and safe and reliable operation is particularly important.

How does the subway screen door ensure the stability of communication?

Figure 1 Beijing’s intricate subway lines

Do you know what the integrated system of the subway comprehensive monitoring system includes?

• Fire Alarm System (FAS);

• Environmental and Equipment Monitoring System (BAS);

• Power Supervisory Control System (SCADA);

• Screen Door/Safety Door System (PSD).

At the same time, the ISCS system is interconnected with the following systems:

• Broadcasting System (PA);

• Closed-circuit television surveillance (CCTV);

• Automatic Fare Collection (AFC);

• Access Control System (ACS);

• Signal System (SIG);

• Clock system (CLK);

• Passenger Information System (PIS);

• Communication centralized alarm system.

Thanks to the complete operation control network, the subway has become more safe and comfortable, and every system is an orderly escort for the safety of the subway. Today, let’s take a look at how the subway screen door system (PSD) works.

The platform screen door of urban rail transit is a high-tech product integrating construction, machinery, materials, electronics and information. It isolates the track from the waiting area of ​​the platform. Close the sliding door.

The subway screen door system based on CAN bus means that the middle PSD (central interface panel), PSA (remote alarm panel) and each DCU (gate control unit) of the system are a network node mounted on the CAN bus. CAN The bus distribution structure can ensure that the failure of one node of Rehe on the network will not affect the normal operation of other nodes in the network, and the whole process control of the screen door through the network, the modification of operating parameters and other tasks.

How does the subway screen door ensure the stability of communication?

Figure 2 The composition frame of the subway screen door system

• PSC: central interface panel, PSC is the core of the screen door/safety control system, each station is equipped with a set of PSC for the screen door/safety door equipment;

• PSD: subway screen door, which can be divided into three parts: sliding door, fixed door and emergency door;

• PSA: remote alarm panel, used for monitoring the status of the screen door, diagnosing the fault of the screen door, running status, etc.;

• PSL: local control panel, the combination of electrical switches on the platform side to control the operation of the screen door on this side, allowing station personnel and train drivers to operate the screen door when the train system control fails;

• DCU: The door control unit is the control device for the sliding door motor. Each sliding door unit of the screen door is equipped with a door control unit, which is installed in the top box.

How does the subway screen door ensure the stability of communication?

Figure 3 Subway screen door system division

The screen door control system still uses hard-wired transmission on some important nodes and commands, such as between PSC and signal system, between PSB and PSL (local control panel), and the sending and feedback of the opening and closing commands of the screen door. To use hard-wired transmission, in addition to the DCU connection via the CAN bus, the PSC communicates with the LESS (Local Environmental Monitoring System) via RS-485. Communicates with PTE via RS232, and communicates with the Display via Ethernet. The subway screen door system is shown in the figure below.

In view of the particularity of the subway operation site, it is necessary to protect the external and own signals, isolate the impact of interference on the bus data communication, and ensure safety and reliability. At present, the authoritative standard for subway screen doors is “CJ/T 236-2006 Urban Rail Transit Platform Screen Doors” issued by the Ministry of Construction of the People’s Republic of China.

This standard specifies the technical requirements, testing and packaging, transportation and storage of screen doors for urban rail transit platforms. In the standard 6.1.2.5 electromagnetic compatibility test, it is clearly required that the screen door must pass GB/T 17626~GB/T 17626.6, GB/T 17626.8, GB/T 17626.11.

How does the subway screen door ensure the stability of communication?

Figure 4 CJ/T 236-2006 Electromagnetic Compatibility Requirements for Screen Door Systems

In order to meet the screen door standard proposed by the Ministry of Construction of the People’s Republic of China, the field data bus interfaces of each DCU, namely CAN-bus interface, RS-485 interface, RS-232 interface, etc., need to be isolated from power supply and communication to completely cut off the ground ring between modules. road interference. Of course, it is also necessary to isolate the power supply at the same time.

How does the subway screen door ensure the stability of communication?

ZLG Zhiyuan Electronics has been focusing on signal isolation and transmission conditioning for 20 years, providing reliable and leading signal isolation and acquisition template-level solutions for the industrial field.

How does the subway screen door ensure the stability of communication?

ZLG Zhiyuan Electronics has launched a surface mount isolation module in order to meet market demands and technological innovations based on years of technology accumulation and customer development trends. Compared with traditional designs, surface-mount products not only have higher integration and reliability, but also support all commonly used SMD packages in the industry. They are suitable for occasions requiring high-stability CAN bus communication, and can maximize the user experience. The production efficiency can help users improve the protection level of bus communication.

How does the subway screen door ensure the stability of communication?

At present, isolated CAN transceivers, isolated RS-485 transceivers, etc. have been launched. The isolation Voltage is up to 3500V, and the ultra-wide temperature adaptation range can conquer complex and harsh industrial sites.

How does the subway screen door ensure the stability of communication?

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In 2020, China’s chip production capacity will be the third in the world, but 60% of the production capacity is from foreign companies

Since the second half of last year, major industries around the world have been faced with a shortage of chips. At the same time, the demand for the entire chip industry is also rising steadily, and semiconductor companies are constantly expanding production and increasing their production capacity.

Especially in terms of mature manufacturing, manufacturers have spared no effort. According to SEMI data, from 2020 to 2024, the global 200mm wafer production capacity is expected to increase by 950,000 wafers, or 17%, to a historical record of 6.6 million wafers per month. new highs.

In 2020, China’s chip production capacity will be the third in the world, but 60% of the production capacity is from foreign companies

Mainland China will become the country with the highest production capacity of 8-inch wafers in the world this year, accounting for about 18% of the global production capacity of 8-inch wafers, surpassing Taiwan and Japan, both of which are 16%.

In fact, in the past few years, China has been expanding its chip production. By 2020, it has accounted for 15% of the global chip production capacity, ranking third in the world, second only to Taiwan and South Korea, and higher than the United States. 12%.

Under such circumstances, Wu Hanming, an academician of the Chinese Academy of Engineering, also pointed out that China needs at least 8 existing SMIC production capacity to improve the current chip supply situation, because the demand for Chinese chips is too high.

In 2020, China’s chip production capacity will be the third in the world, but 60% of the production capacity is from foreign companies

It is precisely because China’s chip production capacity exceeds that of the United States, which makes the United States nervous. After all, chip manufacturing is the highest threshold and the most critical link in the semiconductor industry. The United States does not want its neck to be stuck in China’s hands in the future, so it must vigorously develop Chip manufacturing has recently proposed a $52 billion plan to revitalize the chip manufacturing industry in the United States.

But at the same time, we must also face up to the composition of the 15% of the production capacity, that is, 60% of the production capacity is actually contributed by foreign capital, and the production capacity of Chinese local enterprises only accounts for less than 40%.

In 2020, China’s chip production capacity will be the third in the world, but 60% of the production capacity is from foreign companies

Taking the 2020 data provided by IC Insights as an example, the entire Chinese market produced a total of 22.7 billion US dollars worth of integrated circuits, but of the 22.7 billion US dollars in chips, Chinese local companies only produced 8.3 billion US dollars (accounting for 36% of the 22.7 billion US dollars). .5%), and the rest are contributed by the branches of other major IDMs or foundries in mainland China, such as TSMC, SK Hynix, Samsung, Intel and UMC factories in mainland China.

It can be seen that although my country’s chip manufacturers are doing their best to increase production capacity, the reality is still very severe. As Academician Wu Hanming said, the relationship between supply and demand is still very unbalanced, and the production capacity is still 8 SMIC. The distance, we still need Efforts to increase production capacity, especially the production capacity of local enterprises, what do you think?

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Core Vision, Huada Jiutian, and Gaolun Electronics, who will be the first listed stock on EDA?

The battle for the first EDA listing is here!

On June 2, the three EDAs announced the relevant news about listing counseling at the same time. Core Vision disclosed the relevant information about the listing on the main board of the Shenzhen Stock Exchange, and announced that it would move to the main board. Finish.

The market can’t help but wonder, who can win the first EDA listing?

The Core Vision Science and Technology Innovation Board has turned to the main board

On June 2, Minsheng Securities Co., Ltd. disclosed the basic information table of guidance on the initial public offering of shares by Beijing Core Vision Software Technology Co., Ltd. and its listing on the main board of the Shenzhen Stock Exchange.

It is worth mentioning that the core vision is not the first time to enter the IPO. After the company entered the science and technology innovation board, after a round of inquiries and replies, it withdrew the IPO termination review of the science and technology innovation board.

Core Vision, Huada Jiutian, and Gaolun Electronics, who will be the first listed stock on EDA?

Image source: Official website of the Shanghai Stock Exchange

The company submitted the IPO application documents on the Science and Technology Innovation Board on May 19, 2020, entered the “inquired” status on June 15, 2020, and responded to the first round of inquiries on August 7 of the same year.

On September 29, 2020, the company needs to submit supplementary submissions because the financial information recorded in the issuance and listing application documents has expired. According to Article 64(6) of the Review Rules, the SSE suspends its issuance and listing review.

It is worth noting that the core technology has been disputed by the market before, and more than 5.5 million invoices have been reported by customers as arrears.

The company’s main business is relying on self-developed Electronic design automation (EDA) software to provide integrated circuit analysis services and design services. Since its establishment, the company has established three major business segments: integrated circuit analysis, integrated circuit design and EDA software licensing. These services/products are mainly aimed at IC design companies, integrated device manufacturers, electronic product system manufacturers, scientific research institutes, forensic identification agencies and law firms and other customers. semiconductor-like devices provide process and technology analysis services (such as process/circuit/competitiveness/layout structure analysis, etc.), intellectual property analysis and identification services (such as patent/layout design infringement analysis, etc.), design outsourcing, mass production outsourcing and IP Licensing and other IC design services, as well as a variety of EDA software licensing services.

According to financial data, Core Vision’s revenue in 2017, 2018, and 2019 was 73.7052 million yuan, 114 million yuan, and 160 million yuan respectively; the corresponding net profits in the same period were 25.9363 million yuan and 4022 million yuan respectively. 86,000 yuan and 75,344,500 yuan.

Who will be the first stock listed on EDA?

EDA is a kind of software used to design chips, known as the “mother of chips” and the jewel in the crown of the chip industry. At present, there are no EDA listed companies in China’s A-share market.

In addition to the core vision of receiving listing counseling again, it is worth mentioning that another EDA company, Beijing Huada Jiutian Technology Co., Ltd. (referred to as “Huada Jiutian”) officially launched its listing in February this year. On June 2, the announcement announced the completion of the GEM listing counseling. The company is currently the first company in the domestic EDA industry to choose to be listed on the Growth Enterprise Market.

According to the official website of Beijing Huada Jiutian Technology Co., Ltd., Huada Jiutian was established in 2009 and is committed to providing one-stop EDA and related services for the semiconductor industry. It claims to be the largest and most powerful EDA leading enterprise in China.

In terms of EDA, Huada Jiutian can provide full-process solutions for analog/digital-analog hybrid IC design, digital SoC IC design and optimization solutions, EDA tools for wafer manufacturing, and full-process solutions for flat panel Display (FPD) design. The world’s original leading technology.

The related services provided around EDA include wafer fabrication engineering services and design support services, of which wafer fabrication engineering services include PDK development, model extraction, and yield improvement big data analysis.

In addition, another Shanghai Gailun Electronics Co., Ltd. (hereinafter referred to as “Gailun Electronics”) yesterday (June 2) disclosed the listing counseling summary report, announcing the completion of the listing counseling. The company announced on January 21 that it had accepted listing counseling. Select the listing destination on the Science and Technology Innovation Board.

The main business of Gelun Electronics is to provide customers with EDA products and solutions that have been widely verified and used by the world’s leading integrated circuit design and manufacturing companies for a long time. The main products and services include manufacturing EDA tools, design EDA tools, and semiconductor device characteristics. Test instruments and semiconductor engineering services, etc.

Focusing on the forward-looking vision and layout in the EDA industry, the company has mastered key EDA technologies that are competitive in the international market. The products have been mass-produced and applied by global leading customers for many years, and have strong industry integration capabilities and development potential. At present, the company has three core technologies of manufacturing EDA technology, design EDA technology, semiconductor device characteristic testing technology and nearly 20 subdivided products and services.

Image Credit: Company Announcement

The financial data shows that the revenue of Gelun Electronics in 2018, 2019 and 2020 was 51.9486 million yuan, 65.4866 million yuan and 137 million yuan respectively; the corresponding net profit in the same period was -7.9032 million yuan respectively , -877 million yuan, 27.8917 million yuan.

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How to troubleshoot when encountering Oops prompts during Linux programming?

When engineers develop programs under Linux, have you encountered the “Oops” prompt due to some minor faults in the system? How do you troubleshoot the fault? Look at the code line by line? In fact, it doesn’t have to be that complicated. This article will introduce you to an efficient troubleshooting method for Linux programming.

When engineers develop programs under Linux, have you encountered the “Oops” prompt due to some minor faults in the system? How do you troubleshoot the fault? Look at the code line by line? In fact, it doesn’t have to be that complicated. This article will introduce you to an efficient troubleshooting method for Linux programming.

Before analyzing Oops, let’s take a look at the following example, using GPIO interrupt for power-down detection, refer to the driver framework of “Embedded Linux Development Course Part II”, and design the following block diagram:

How to troubleshoot when encountering Oops prompts during Linux programming?

The ideal process at the beginning of the design of this framework is: application startup -> program initialization -> application open device -> waiting for an interrupt event, but in actual project development, many unpredictable things often happen. If Xiao Wang is tuning the Qt application and finds that Lao Wang’s process is always printing, then do not let Lao Wang’s process start automatically. Appears, new additions appear, then the cause is definitely in the new code” inertial thinking, thinking that it is caused by the newly added Qt, and then Xiao Wang keeps testing and constantly looking for bugs… This has passed ten years.

But the reason is actually that Xiao Wang does not have an open device, that is, the driver layer does not initialize the timer queue, then the queue triggered by 50ms in the interrupt handler function is a null value. When the pointer is null, the Linux kernel will of course remind you “ouch”, and The occasional prompt is actually because the power supply is loose from time to time, and the gpio detects that the power is off, so an interrupt is triggered.

In fact, such cases are very common. The original idea is A->B->C, but the actual use is A->D->C, or there is a variable in the driver that forgets to initialize, etc. At this time, analyzing Oops can be very useful. Solve problems quickly. Then we will use the standard driver in Linux to trigger an Oops. You are right, there is such an exception in the standard source code of the Linux kernel, and we can also fix this problem.

Using our EasyARM-iMX283 development board, the kernel source code is Linux-2.6.35.3.tar.bz2 in the CD-ROM. Please refer to the CD-ROM for the compilation method. We need to change the backlight driver of the lcd to ko mode.

How to troubleshoot when encountering Oops prompts during Linux programming?

After burning the new kernel, loading the newly compiled drivers/video/backlight/mxs_bl.ko file will prompt the following Oops information:

How to troubleshoot when encountering Oops prompts during Linux programming?

At first glance, this information looks like gibberish, but as long as you analyze it layer by layer, you will find that this information has already told us the reason for the error. Next begins our Oops analysis journey.

1. Main error message

How to troubleshoot when encountering Oops prompts during Linux programming?

The type used to prompt the error, here means using a null pointer.

2. Operation entrance

How to troubleshoot when encountering Oops prompts during Linux programming?

The operation used to prompt the error, here means that there is an error when loading the mxs_bl module, which corresponds to the loading operation insmod mxs_bl.ko.

3. PC pointer

How to troubleshoot when encountering Oops prompts during Linux programming?

It is used to prompt the PC pointer position when an error occurs. The PC pointer is the address of the current program running point. The prompt here indicates that the error function is regulator_set_current_limit, and the offset address is 0xc.

4. LR pointer

How to troubleshoot when encountering Oops prompts during Linux programming?

It is used to indicate the position of the LR pointer when an error occurs. The LR pointer is the last function name and entry offset of the calling sub-function. Here, it indicates that the last function is set_bl_intensity, and the offset address is 0xd8. i.e. error when set_bl_intensity calls regulator_set_current_limit.

5. Register value

How to troubleshoot when encountering Oops prompts during Linux programming?

It is used to record the value of each register when an error occurs. Comrades who are familiar with assembly can study this information.

6. Error process information

How to troubleshoot when encountering Oops prompts during Linux programming?

The process id number and process name used to prompt errors. The error process is insmod, and the PID number is 2261. In a multitasking system, there may be multiple PIDs calling the same interface.

7. Stack information when error occurs

How to troubleshoot when encountering Oops prompts during Linux programming?

It is used to prompt the register information saved in the stack when an error occurs. When the program is interrupted or a subroutine is called, the stack operation will be performed, that is, the running environment will be saved to the stack to ensure that the running environment will not occur after exiting the interrupt or jumping out of the subroutine. Change.

The stack information here records the environment information when the program is running. From it, we can find many LR addresses, so as to analyze the function call relationship, which has a similar effect with the information in the next paragraph.

8. The backtracking relationship of function execution

How to troubleshoot when encountering Oops prompts during Linux programming?

It is used to represent the calling relationship of the function. Through this information, we can know the entire execution process of the function and its function calling relationship. Finally, the function execution process sorted out is as follows:

How to troubleshoot when encountering Oops prompts during Linux programming?

From this, we can see the familiar init function, probe function, and understand where the operation process performed under the probe function is wrong. Now we know the execution flow of the code and the location of the PC pointer that made the error, but we still can’t see the code. We only see a string of numbers at the error pointer, so let’s operate it next to change the data of the pc pointer to meaningful code.

The first step is to identify where the error code is
The binary files involved in this experiment include the burning firmware of the kernel and the ko file of the driver, so the first step of analysis needs to determine whether the error code is in the kernel firmware or the ko file.

First get the scope of the kernel code, disassemble the kernel with the following command.

How to troubleshoot when encountering Oops prompts during Linux programming?

Check out the format of this file as follows:

How to troubleshoot when encountering Oops prompts during Linux programming?

The number of rows in the first column, the running address in the second column, the binary code in the third column, and the assembly code in the fourth column. Since the second column is the running address, it is equivalent to the value of the pc pointer when the program runs to this row. In this way, as long as you look at the head and tail of this file, you can know that the PC pointer range of the kernel code is: c0008000~c0562338.

According to the register value in the previous step 5, the PC pointer is c02f1878 when the error occurs, that is, it is within the scope of the kernel source code.

The second step is to analyze the error statement of the error function
Then according to the PC pointer in step 3, the assembly code of regulator_set_current_limit is obtained, as follows:

How to troubleshoot when encountering Oops prompts during Linux programming?

The function entry address is c02f186c .
In step 3 the PC pointer points to the offset address “PC is at regulator_set_current_limit+0xc”.
PC = 0xc02f1878 = 0xc02f186c + 0xc, which corresponds to the assembly code address.

The third step is to find the C language code of the error function
This step can be said to be the most difficult, because there are many layers of kernel code, and there may be many copies of the function with the same name. Several copies may be compiled into the kernel (local functions declared statically), or they may not be compiled into the kernel. Analyze which section.

I used some small methods. First, add garbled characters to the entry of each function of the same name, let the compiler filter out the files compiled into the kernel (because of garbled characters, so the compilation will report an error), and then add print statements to the remaining functions, Usually after the first step, there are only two or three optional targets, and the code can be further confirmed by printing.

The following is the filtered C language code.

How to troubleshoot when encountering Oops prompts during Linux programming?

Seeing that this seems to locate the function, but for those who are not familiar with assembly, C and assembly are still not related, it seems to have entered a dead end, but don’t be discouraged, from the above assembly code, we know that the function name is The first address of the function, then calling the sub-function needs to let the CPU know the sub-function name, so how does the assembly call the sub-function? Use the bl command, bl+subfunction name. Since assembly has such a feature, let’s look at assembly code.

Line 582734 above “bl c0493104 “This sentence calls a subfunction, and then look at the statement in C that calls this function.

How to troubleshoot when encountering Oops prompts during Linux programming?

Then the result is obvious, it is impossible to define a variable and report an error, so the only statement that may be wrong is struct regulator_dev *rdev = regulator->rdev. Similarly, the first half of this sentence is just to define an rdev variable, and then combine it with the kernel to give The prompt comes out – a null pointer, so the error is that regulator->rdev is a null pointer.

The ultimate question comes down to why regularar->rdev is a null pointer. This part of the code and reasoning needs to be dug deeper, and the workload is beyond the scope of this article, so the author boldly speculates that it is similar to the A->B->C model above. So we need to assign a value to this resource before calling it when it exists.

At this time, we need to take out the backtracking relationship diagram of the function execution in step 8. Since we know that the rdev of the input parameter regulator of the last function in this figure is empty, then we care about the regulator structure and its meaning. From the meaning of the structure, we can know how to assign a value to it.

How to troubleshoot when encountering Oops prompts during Linux programming?

Search for the keyword “regulator” or “regulator =” in the relevant code file (it is recommended to search for this, because this is the assignment statement) to get the following code.

How to troubleshoot when encountering Oops prompts during Linux programming?

Analysis of this function shows that the regulator is actually a member of pdata. It needs data to initialize, so the next thing is simple. Find a place in the backtracking relationship to insert the data of data into pdata, just this function is initialization. The regulator, then use it directly.

Adding this paragraph to this position within the probe function implements the assignment of this variable between mxsbl_probe and mxsbl_do_probe.

How to troubleshoot when encountering Oops prompts during Linux programming?

In this way, the ko file can be loaded normally after recompiling.

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A hundred schools of thought contend, so how should I choose among various industrial Ethernet protocols?

At present, the overall mainstream trend of global industrial manufacturing development is automation and intelligence. Under the guidance of this trend, the market for a series of industrial intelligence and automation equipment industries has expanded rapidly. A complete industrial intelligence and automation solution includes several different devices such as PLC, system control software, and industrial robots, and these components need to be connected by industrial Ethernet to form a unified whole. High performance, integration of factory equipment and IT systems, and demand for industrial IoT are driving the growth of Industrial Ethernet.

Annual Analysis of Industrial Networking Market by HMS Industrial Networks

According to the 2017 Industrial Network Market Share Report released by HMS, Industrial Ethernet is growing faster than in previous years, with a growth rate of 22%. Industrial Ethernet now accounts for 46% of the global market, up from 38% last year.

In specific communications, EtherNet/IP and PROFINET have the largest share, with PROFINET as the main market in Central Europe and EtherNet/IP in North America. It is followed by EtherCAT, Modbus-TCP and Ethernet POWERLINK.

In real-time industrial Ethernet, EPA, EtherCAT, Ethernet Powerlink, PROFINET, Ethernet/IP, SERCOS III are the main contenders.

Development direction of industrial Ethernet


The high-speed operation of the information age will make enterprises face the following challenges in the future market competition:

 1. Reduce the time to market of products, which requires enterprises to have lower product update time, higher product technology, and greater data volume;

2. Increase flexible equipment, because customized production and changing market demands require enterprises to have higher production capacity;

3. Improve product quality, which requires enterprises to conduct real-time monitoring in the production process, obtain quality data feedback in a timely manner, and make corresponding responses and decisions;

4. Improving production efficiency and higher utilization of resources and energy will become the key factors for future enterprise competition.

5. The most important point is to ensure data security, that is, information security.

And the future demand of enterprises for industrial communication will also develop in these directions with the increase of market competition and challenges:

1. Higher bandwidth, the current communication has reached 100Mbps, the future industrial communication can apply higher bandwidth, and has definite scalability;

2. The standard is unified, and the communication based on the IP standard increases greatly;

3. Flexible configuration, industrial Ethernet will be able to automatically assign the link device name and IP address;

4. Strong compatibility, fully compatible with IEEE, IETF, IEC and other related standards,

In addition, from the perspective of the development prospects of industrial Ethernet, in the future industrial communication market, from the field, control layer, workshop layer, company layer to cloud platform, from the bottom layer to the upper layer, real-time communication and open network communication will be integrated in In the same system, the overall communication is realized.

Industrial Ethernet Protocol


When Ethernet is used for industrial control, the real-time communication, the object used for system configuration and the application protocol of engineering model are embodied in the application layer. Until the 21st century, there is no unified application layer protocol.So, how did these agreements come about, what are the differences between them, what are the advantages of each, what are the limitations, etc. Before this, the editor has sorted out and published them for you, so I will not I repeat them one by one. For details, please click the following link: Read the original guide

Still can’t tell the difference between various industrial Ethernet technologies?After reading this, you will understand

Seven Elements of Industrial Ethernet

Before using industrial Ethernet in the factory production layer, you must understand its seven elements, which are also the reference requirements and considerations for the industrial production layer to choose which Ethernet technology to use. Here, we take the Profinet standard as an example to introduce you one by one.

 1. Network layout

Different from the network topology layout of the office, the industrial Ethernet architecture needs to have some additional functions, such as high-speed redundancy, because it often faces changeable unexpected situations, so the industrial Ethernet will adopt a variety of different topology network layout methods. (star, ring, tree, line), and use shielded cables, metal connectors, with higher heat and shock resistance. In addition, the switches of industrial Ethernet are generally configured and maintained by the corresponding automatic control system integrators.

 2. Communication protocol

The most important thing for control system integrators is to realize that Ethernet is just a network architecture, and to make it possible to communicate between automation devices, you need an industrial-grade communication protocol. The IEEE 802.3 Ethernet standard defines the wiring methods, data read and write rules, and the structure of the Ethernet architecture. Although different devices using this network standard can communicate on the same network segment, the premise is that they must use the same network protocol, or “communication language”. Profinet is a communication protocol designed for industrial applications, providing functions for distributed I/O, machine-to-machine connectivity, machine safety, and motion control.

 3. Processing power

It’s not simply how fast the network is, but how quickly and precisely the data gets where it’s supposed to go. The processing power of the network is undoubtedly one of the most critical factors, and its measurement standard is the amount of network data transmission per unit time. The only way to improve this performance is to reduce the number of cycles in the communication stack. The number of cycles in the Profinet communication stack is ten times less than a standard Ethernet TCP/UDP tool. This is due to the fact that Profinet has dedicated an Ethernet real-time channel for some important time-critical work, while at the same time its configuration, diagnostics, routing, and “bulk data transfer” communications are all over standard TCP/ The IP tunnel is complete.

  4. Network configuration

The setup of the network is simple, but more importantly, the programming to achieve communication must not be too complicated. Profinet enables device-to-device communication through configuration rather than programming. Instead of the traditional programming and debugging method, system integrators and end users can save at least 25% of the construction and commissioning time through an object-responsive method of configuring internal communication between devices.

  5. Advance planning

It is not enough to consider the application at hand, the current Ethernet must be able to meet the needs of all possible applications in the future. Profinet enables users to implement at their own pace, using only a single Ethernet network, a highly integrated solution for different control functions such as point-to-point communication, distributed I/O, machine safety, motion control and data acquisition ) of the automatic control system. It is also prepared for possible future expansion.

 6. Retrofit of old systems

The elements of Industrial Ethernet are not limited to Ethernet itself. How to integrate and work properly with existing networks and machines provided by different suppliers is one of the issues that must be considered. Since Profinet uses standard Ethernet switches and uses TCP/IP protocol components, Profinet-based systems should be able to apply to the entire autonomous network without the need for additional high-end switches or special functions such as IGMP snooping and VLAN. Profinet also provides solutions for connecting products from different suppliers to the same network. Through XML, it handles each machine as a component, relatively independent of the internal core control system, which is the concept of automation with components as the control unit.

  7. Fees

For industrial Ethernet networks, the most important expenses are not the components of building the network, but the design, installation and maintenance parts. If you want to save money, you must work hard on these three parts. Profinet and other similar industrial Ethernet architectures use the results of IT technologies, such as OPC and SNMP, to monitor and Display the status of the network. In addition, its diagnostic function can directly reflect the state of the network on the automatic control system including plc and SCADA system. In this way, configuration settings and fault finding can be completed in the central control room, which greatly simplifies the operation.

 

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