How to solve the conflict between high failure rate and insufficient efficiency of car "smart key" programming

With the booming automotive electronics industry, automotive manufacturers are increasingly using electronic components. However, the conflict between the high-capacity demand and the inefficiency of the original tool programming failure rate is increasingly prominent. What is the reason? Today, let us talk from the car "smart key".

First, the phenomenon

When many smart key manufacturers start production, they use the 2-Link emulator provided by the chip to burn. 2-Link has a third-party calling interface, which can realize semi-automatic mass production programming. We know that the strength of 2-Link is simulation. It is a unique tool for the development stage, but it does not show stable performance in strict production. Many users respond, and when using 2-Link production, there will be a certain probability of burning. Bad phenomenon. In the rigorous automotive electronics industry, demanding nearly 100% yield, it is clear that the effect of 2-Link is difficult to accept.

Figure 1 NXP simulation tool

Second, the reason

Part of the reason for the instability of the programming is that the driver's pin driving ability is not strong. We know that online programming is not only related to the programmer, but also has a great relationship with the wiring. As the wiring grows, the programming signal will It gradually decays, and the driving ability of the pin determines the degree of attenuation of the signal.

Some online support programmers on the market directly lead to the IO port of the internal control chip or the pin of the FPGA as the input and output of the programming signal, and the driving ability is weak. When the user's wiring is relatively long (generally greater than 30cm), Signal distortion occurs, resulting in unstable programming. For the car key manufacturers, in order to improve the production efficiency, the programming method of the jigsaw is adopted, so the user needs to draw the wire longer when making the jig, which leads to unstable programming of some programming tools.

Figure 2 Multi-panel burning

Third, the solution

In the face of customer's production problems, we have developed a mass-produced online programmer P800isp that can be tailored for different customers with the experience of ten-year simulator and programmer development. Through the multi-channel signal amplification processing, the driving ability of the programmer is enhanced, and the problem that the burning line is too long to be stably burned is effectively solved. As shown in the figure below, the P800isp programmer compares with the waveform of a supported online programmer when the programming line is 25cm long.

Figure 3 P800isp compared with some programmer waveforms

In addition to the influence of the length of the line, programming is also related to the material and thickness of the line. It is recommended that the user select a material with strong conductivity and a thicker wire diameter when making wiring. In addition, if the wire is introduced for a long time (more than 50cm) because of the particularity of the burning environment, the communication frequency can be appropriately reduced to improve the stability of the programming, as shown in Figure 4, for the P800isp programmer. The interface of communication frequency can adapt to various burning environments.

Figure 4 adjustable frequency

In summary, the original tool name is an emulator, which is naturally more suitable for circuit simulation and debugging, but it can not meet the complex burning environment requirements in mass production. The P800isp has a purer and stronger driving signal, and can be “ One machine for universal use, the current PCF79XX, NCF29XX and other series of chips commonly used in keyless entry systems have been supported, truly one-time payment, lifetime use.