Yokogawa electric dlm2000 mixed signal oscilloscope meets the challenge of embedded design
at present, almost all electronic products designed and produced belong to embedded systems, which may include microprocessors, microcontrollers, DSP, ram, flash memory, EPROM, FPGA, a/d-d/a and other i/o. Yin Xiaogang, director of the embedded test project Department of Yokogawa, said that Turkey experienced two consecutive economic crises in 1999 and 2001. Due to the need to measure various signals in the design of embedded systems, and more and more serial buses, such as I2C, SPI, can, UART and Lin, are being used to replace the internal parallel bus. Its complexity has brought many challenges to the design engineers in debugging
according to a survey of mixed signal oscilloscope users, 70% of users said they needed logic input function, 36% of users thought that channels could meet their testing needs, and the engineering fields that most needed 8-channel logic input included processor debugging, inter module communication evaluation and hardware control
Yokogawa electric dlm2000 series mixed signal oscilloscope
Yokogawa electric recently launched a new dlm2000 series mixed signal oscilloscope to provide a useful solution to solve the above problems. Dlm2000 series adopts the vertical thermoelectric conversion material and the post utilization design of solar cells, and is equipped with 8.4-inch XGA (1024x768) TFT-LCD display, including six models. The bandwidth range is 200mhz-500mhz, the storage depth is 62.5m-125mpts, and the sampling rate of 2.5gs/s and 8-bit logic input are provided at the same time, which can capture the signal activity in a long time window with high resolution
Yin Xiaogang stressed that for embedded systems in digital home appliances or automotive control industries, there are more and more requirements for "digital control + analog waveform observation". The existing 4-channel analog oscilloscope has too few measurement channels, which is difficult to deal with the needs of some projects. For example, connect the internal equipment to the SPI bus (3-wire or 4-wire) and observe the analog signal driven by the motor; Or observe the timing between the digital control signal and the internal analog signal in the automobile engine control unit (ECU)
dlm2000 adopts a relatively flexible MSO input function, which can switch one of the analog input channels (CH4) to 8-bit logic input and display signals. Therefore, this series can be used for both traditional 4-channel analog input and mixed signal oscilloscope (composed of 3 analog channels and 1 8-bit logic input channel); The combination of 4 analog channels and 8-bit logic input can be used as a trigger source. If more than 5 channels of signals need to be tested, dlm2000 allows the use of logic input to analyze two types of buses (I2C and SPI) at the same time, and can synchronously observe multiple analog waveforms. In order to enable engineers to observe waveforms for a long time under the condition of high sampling rate, so as to evaluate the quality of communication waveforms (noise, conversion time, etc.), the continuous acquisition storage length of dlm2000 series is designed as - Development Center 12.5mpts. This means that the dlm2000 can observe 500kbps can bus signals at a sampling rate of 2.5ms/s during waveform acquisition with a time length of 5 seconds; In the single acquisition mode, the maximum storage depth of dlm2000 is 125 mpts. According to the formula "sampling rate = storage length/waveform acquisition time", after setting the same waveform acquisition time, a longer storage depth can observe the waveform at a higher sampling rate. At the same time, the acquisition time range of dlm2000 also reaches 500s/div, which can capture 10000hz signals up to 5000 seconds
the new dlm2000 series also strengthens the historical storage function and time marking, so as to trace and analyze the waveform collected in the past. When the storage length is 1.25kpts, the dlm2000 can accumulate up to 20000 screens of historical data. However, problems also follow. Deep storage usually represents signal activity equivalent to thousands of screens, which makes it extremely difficult to quickly find relevant information about a specific problem. Yin Xiaogang said that on the one hand, dlm2000 is equipped with a search engine. By setting conditions similar to trigger, engineers can search for the desired data from the collected waveform, and can display the historical waveform screen by screen or automatically playback it like DVR. On the other hand, the time marking accuracy of the waveform retained in the memory is optimized, so that it is increased from the previous 10ms to the current 50ns, and the resolution is proportional to the sampling rate
when debugging the system design, it is not easy for engineers to confirm abnormal phenomena and clarify the operating conditions of the circuit in a short time. In order to increase the chance of catching abnormal phenomena, the most common means for engineers is to improve the performance of data processing. For example, increase the number of samples per second, generate as much information as possible on the basis of a large number of sampled data, and then generate images. "Scopecore is an engine specially developed by Yokogawa electric for detecting abnormal signals," Yin Xiaogang pointed out. "It provides high waveform acquisition rate, improved data processing ability and waveform display performance, and can carry out signal 2. Waste plastic crushing and trigger detection."
it is reported that through the scopecore engine, the switching between simulation and logic input is carried out in the data acquisition part. Since the trigger delay between each channel and logic bit is less than 200ps, and the obtained logic data is stored in the area of analog channel 4, there is no difference between the flow of data and analog data. Therefore, even if the logic display is turned on, the high waveform acquisition rate can be maintained to ensure that abnormal signals are not missed. Similarly, the display of logic waveform is not superimposed with the display of analog waveform, so the timing relationship between analog signal and logic signal can be observed intuitively
dlm2000 is a small oscilloscope for testing 4-channel signals. In the limited panel, the vertical axis scale knob is shared by the channels. For the consideration of humanized operation, Yokogawa electric introduced the LED indicator light of the scale knob this time. Through the color displayed by the LED indicator light, the engineer will immediately know the channel controlled by the current scale knob. In addition, the series also supports double area scaling. Engineers can display waveform data, waveform image data, thumbnails of waveform area files and other contents on the screen. (shaolefeng)
LINK
Copyright © 2011 JIN SHI