Serial Signal Compliance Analysis And Verification

In recent years,the manufacturing industry and other enterprises have introduced serial bus standards to improve the competitiveness of their products and meet market demands.Different serial bus standards have corresponding regulatory agencies to formulate specific measurement specifications.Only when the bus products involved are measured by special equipment and all parameter measurement results meet the requirements of the specifications,can the produced products be considered to meet the compliance requirements,and Compatible with other manufacturers’ products,this process is "compliance testing".Combining digital oscilloscope and serial bus standard,this paper has carried out indepth research on the consistency analysis function of oscilloscope serial signal,and designed the function of serial signal consistency analysis software.This function can perform conformance testing for MIPI D-PHY（Mobile Industry Processor Interface D Physical Layer）physical layer,DDR2 SDRAM（Double-Data-Rate Two Synchronous Dynamic Random Access Memory）physical layer,and physical layer of some specific Ethernet standards.The details are as follows:1.MIPI D-PHY physical layer conformance analysis module: first analyze the basic structure and transmission principle of MIPI D-PHY,take MIPI D-PHY specification as the standard,and measure the measurement algorithm involved in the MIPI D-PHY physical layer conformance test Conduct specific analysis,including study of measurement methods for all measurement parameters in high-speed mode and lowpower mode.Among them,the measurement of some specific parameters in the highspeed mode needs to search,locate and count the template data in combination with the improved KMP algorithm.The measurement results are obtained through the corresponding algorithm,and the test results are compared with the range required by the specification to determine whether the product is qualified.2.DDR2 SDRAM physical layer consistency analysis module: Based on the DDR2 SDRAM standard formulated by JEDEC（（Joint Electronic Device Engineering Council））,the test items are divided into three categories according to test signals and test types:single-ended signal test,differential signal test and timing parameter test.By analyzing the differences between read and write signals,the mixed read and write signals are separated by phase and amplitude differences.Subsequent test parameters are mostly measured based on the read and write separated signals.3.Ethernet physical layer consistency analysis module: First,briefly describe the relevant principles of Ethernet transmission,summarize the signal characteristics output by 10BASE-T and 100BASE-TX network interfaces,common faults and characteristics of the physical layer,and combine them.The Ethernet standards have designed the conformance test module,which mainly includes the construction and matching of the signal template,the 10BASE-T and 100BASE-TX test modules,and the control method of the test packet.Finally,test and verify the measurement algorithms of the above three protocols,and compare the software test value with the oscilloscope cursor value to verify the correctness of the measurement value.All three modules can operate and measure normally,which verifies the accuracy of the test modules.