A testing device for computer VGA interface

Abstract

This utility model discloses a testing device for a computer VGA interface, comprising: a video conversion module, the input of which is connected to an external VGA interface to receive analog video signals and convert the analog video signals into HDMI signals; an FPGA module, the input of which is connected to the output of the video conversion module and is used to receive the HDMI signals; the FPGA module has a built-in video loop-out unit, a format conversion unit, a frame buffer, and a CRC error detection unit; an HDMI output interface, the input of which is connected to the output of the video loop-out unit of the FPGA module and is used to connect to an external display device; and a communication interface module, including an asynchronous transmission standard interface and a universal serial bus interface, the communication interface module being electrically connected to the FPGA module and used to receive control commands from a host computer. This utility model is low in cost, accurate, efficient, and can simultaneously integrate video and audio testing functions.

Description

Technical Field

[0001] This utility model relates to the field of computer interface testing, and in particular to a testing device for computer VGA interfaces. Background Technology

[0002] The Video Graphics Array (VGA) interface, as a traditional analog video output interface, remains widely used in various computers, servers, and industrial control equipment due to its simple structure and low cost, for implementing basic display functions. Therefore, rapid and reliable testing of the functionality and performance of a device's VGA interface is a crucial step in the manufacturing and quality control processes of electronic products.

[0003] Currently, VGA interface testing primarily relies on two methods: one is manual subjective judgment, where operators visually inspect the output image for abnormalities such as screen tearing, flickering, or color distortion by connecting it to a monitor; the other is quantitative measurement using dedicated and expensive video signal analyzers. However, these existing solutions have significant drawbacks: manual inspection is highly subjective, easily affected by factors such as operator experience and visual fatigue, making it difficult to detect subtle image flaws, resulting in low testing efficiency and accuracy, and it cannot simultaneously test audio interfaces. While high-end video signal analyzers can achieve precise measurements, their high equipment procurement costs and complex operation typically limit their application to laboratory environments, hindering widespread use in production lines and other scenarios requiring large-scale, rapid testing. Furthermore, traditional testing methods usually only target video signals, lacking integrated and automated testing capabilities for the device's audio input / output functions. In actual testing, audio detection often requires additional equipment and procedures, increasing testing complexity and time costs.

[0004] Therefore, the industry urgently needs an automated solution that is cost-effective, accurate, efficient, and can integrate video and audio testing functions to meet the dual demands of modern production lines for efficiency and reliability. Utility Model Content

[0005] The purpose of this invention is to provide a testing device for computer VGA interfaces that is low in cost, accurate, efficient, and can simultaneously integrate video and audio testing functions.

[0006] The technical solution of this utility model is: A testing apparatus for a computer VGA interface, comprising: A video conversion module, whose input terminal is used to connect to an external VGA interface to receive analog video signals, and is used to convert the analog video signals into HDMI signals; The FPGA module, whose input is connected to the output of the video conversion module, is used to receive the HDMI signal; The FPGA module has a built-in video loop-out unit, a format conversion unit, a frame buffer, and a CRC error detection unit. An HDMI output interface, whose input end is connected to the output end of the video loop-out unit of the FPGA module, is used to connect to an external display device; The communication interface module includes an asynchronous transmission standard interface and a universal serial bus interface. The communication interface module is electrically connected to the FPGA module and is used to receive control commands from the host computer.

[0007] Preferably, it also includes an audio input / output interface, the input of which is used to directly connect to the host audio source, and the output of which is connected to the audio input of the FPGA module; The FPGA module also has a built-in audio analysis unit, the output of which is connected to the feedback input of the dedicated audio input / output interface.

[0008] Preferably, the CRC error detection unit integrated in the FPGA module is used to perform real-time cyclic redundancy check on the video data stream.

[0009] Preferably, the audio analysis unit integrated in the FPGA module is used to analyze the signal-to-noise ratio and frequency response characteristics of the audio signal. The advantages of this utility model are: 1. This utility model uses FPGA to execute core control logic, which can automatically complete video signal format conversion, loop-out, buffering, and CRC error detection, and automatically perform signal-to-noise ratio and frequency response analysis of audio signals. It completely eliminates the subjectivity and random errors of manual inspection, and the test results are objective, accurate, and quantifiable, greatly improving the testing efficiency and consistency of products on the production line.

[0010] 2. This invention adopts an FPGA-based hardware architecture, replacing expensive and bulky professional video signal analyzers. The device is compact and significantly reduces costs, while simultaneously integrating video and audio testing functions, achieving "dual-purpose functionality." This eliminates the cost and process of configuring additional audio testing equipment, enabling the widespread application of high-performance automated testing in large-scale production environments. Attached Figure Description

[0011] The present invention will be further described below with reference to the accompanying drawings and embodiments: Figure 1 This is a schematic diagram of the testing device for computer VGA interfaces according to this utility model. Detailed Implementation

[0012] like Figure 1As shown, this embodiment provides a testing device for a VGA interface, the core components of which include: a video conversion module, an FPGA module, an audio interface module, a communication interface module, and a power supply module.

[0013] The video conversion module is implemented using a VGA to HDMI conversion chip and its peripheral circuitry. Its VGA input port (DB15 female connector) connects to the VGA output interface of the computer or server under test via a VGA cable, receiving RGB analog signals and horizontal and vertical sync signals. This module is responsible for performing analog-to-digital conversion (ADC), scaling, and format encoding on the analog signals, outputting digital video signals conforming to the HDMI standard (such as TMDS signals conforming to the DVI 1.0 standard).

[0014] The HDMI output of the video conversion module is connected to the I / O Bank configured as an HDMI input on the FPGA chip via a ribbon cable.

[0015] The HDMI output interface is a standard HDMI Type A female connector, whose signal input terminal is directly connected to the I / O pin configured as TMDS output on the FPGA chip for video loop-out.

[0016] The audio interface module includes a 3.5mm stereo audio jack (serving as both input and output) and an audio codec chip. The audio output of the host under test (DUT) is connected to the input of this jack via an audio cable, sending the analog audio signal to the audio codec. The codec converts the analog audio into a digital signal and transmits it to the FPGA. Simultaneously, the digital audio signal processed by the FPGA is converted back into an analog signal by the codec and played back from the output of the jack to the microphone input port of the DUT, thus achieving audio loopback testing.

[0017] The communication interface module includes: A USB interface chip that implements USB to FIFO or USB to GPIO functions for high-speed data interaction with a host computer.

[0018] A UART-to-USB chip provides a serial communication port for receiving simple control commands and log output. Both interface chips are connected to the FPGA's general-purpose I / O pins.

[0019] The device is powered by an external 12V DC power adapter, and internally generates various voltages such as +5V, +3.3V, +2.5V, and +1.2V through a linear regulator (LDO) and a switching regulator (DC-DC) to provide stable operating voltages for each module.

[0020] The host computer test software sends control commands to this device via USB or UART interface. The FPGA parses these commands and executes corresponding operations, such as: switching the working mode of the video conversion module to adapt to different input resolutions; starting or stopping a specific audio test; querying the current video CRC status, etc. All test results and status information are fed back to the host computer in real time through the communication interface, and the host computer software generates a test report based on this.

[0021] Video testing process: The VGA analog signal from the device under test is input to the video conversion module and converted into a digital HDMI signal.

[0022] The HDMI signal is sent to the FPGA. The logic units inside the FPGA perform the following operations: a) Signal format conversion: Convert the input video stream into an intermediate format for easier subsequent processing.

[0023] b) Frame buffer: Video frame data is written to an external DDR3 SDRAM for buffering to achieve frame synchronization and comparative analysis.

[0024] c) Real-time error detection: Performs real-time cyclic redundancy check (CRC calculation) on the input video data stream. If N consecutive packets (N is configurable, default is 1) fail the check, an error report is sent to the host computer via the communication interface.

[0025] d) Video Loopout: Simultaneously, the raw or converted video data stream is sent directly to the FPGA's HDMI output pin for output to an external display. Operators can observe the displayed image in real time and perform intuitive quality comparisons.

[0026] Audio testing process: The audio output signal of the host under test enters the audio codec through the 3.5mm interface, is converted into a digital audio stream, and then transmitted to the FPGA.

[0027] The audio analysis unit inside the FPGA performs the following: a) Audio loop-out: The received audio data is sent back to the audio codec via the I2S interface, either directly or with a slight delay. After being converted into an analog signal, it is output to the host microphone port to test whether the audio loop is clear.

[0028] b) Performance Analysis: The received audio data is sampled and analyzed. For example, frequency response characteristics are calculated, as well as the signal-to-noise ratio (SNR) and total harmonic distortion (THD+N). These quantization results are uploaded to the host computer software for display via a USB interface.

[0029] The above embodiments are only for illustrating the technical concept and features of this utility model, and are intended to enable those skilled in the art to understand the content of this utility model and implement it accordingly. They should not be construed as limiting the scope of protection of this utility model. All modifications made in accordance with the spirit and essence of the main technical solution of this utility model should be included within the scope of protection of this utility model.

Claims

1. A testing device for a computer VGA interface, characterized in that, include: A video conversion module, whose input terminal is used to connect to an external VGA interface to receive analog video signals, and is used to convert the analog video signals into HDMI signals; The FPGA module, whose input is connected to the output of the video conversion module, is used to receive the HDMI signal; The FPGA module has a built-in video loop-out unit, a format conversion unit, a frame buffer, and a CRC error detection unit. An HDMI output interface, whose input end is connected to the output end of the video loop-out unit of the FPGA module, is used to connect to an external display device; The communication interface module includes an asynchronous transmission standard interface and a universal serial bus interface. The communication interface module is electrically connected to the FPGA module and is used to receive control commands from the host computer.

2. The testing apparatus according to claim 1, characterized in that, It also includes an audio input / output interface, the input of which is used to directly connect to the host audio source, and the output of which is connected to the audio input of the FPGA module; The FPGA module also has a built-in audio analysis unit, the output of which is connected to the feedback input of the audio input / output interface.

3. The testing apparatus according to claim 1, characterized in that, The CRC error detection unit integrated in the FPGA module is used to perform real-time cyclic redundancy check on the video data stream.

4. The testing apparatus according to claim 2, characterized in that, The audio analysis unit integrated in the FPGA module is used to analyze the signal-to-noise ratio and frequency response characteristics of the audio signal.

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