Multi-channel AD acquisition system based on DSP-FPGA

Abstract

The invention relates to the technical field of universal expansion interface control systems, in particular to a multichannel AD acquisition system based on a DSP-FPGA (Digital Signal Processor-Field Programmable Gate Array). Comprising an acquisition transmission plate; the acquisition and transmission board comprises an FPGA module which is mainly used for controlling and reading 20 analog-to-digital conversion chips LTC, storing LTC output signals into memories RecvRAM1-RecvRAM5 in a distributed manner, further completing down-conversion processing through a plurality of 16-channel DDCs, converting array element echo signals into baseband I / Q digital signals, and storing the baseband I / Q digital signals into RIRAM; and the DSP is notified to read the data at the FPGA end to the DDR2 through the FIFO half-full flag bit. And the DSP module is mainly used for receiving and processing a network control command, controlling switching of a state machine at the FPGA end, receiving a data packet from the FPGA end and sending data through a network uplink. The carried analog-to-digital conversion chip converts input 80 paths of conditioning signals into digits, and the sampling rate of 5M is supported at most; and the maximum data throughput rate of the system is not less than 400Mbps through 1000M Ethernet data output.

Description

technical field [0001] The invention relates to the technical field of a universal extended interface control system, in particular to a DSP-FPGA-based multi-channel AD acquisition system. Background technique [0002] Basic situation of traditional technology: ADC includes three basic functions: sampling, quantization and coding. The sampling process is to discretize the analog signal in time to make it a sampling signal; quantization is to discretize the amplitude of the sampling signal to make it a digital signal; and encoding is to convert the digital signal into a form acceptable to the digital system. We know that data acquisition cards are generally divided into two categories in terms of hardware architecture. The first type is a synchronous acquisition card, that is, each channel of the acquisition card has a separate ADC (analog-to-digital converter) and amplifier. Such an acquisition card is suitable for occasions where the signal timing is very strict, and the s...

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Problems solved by technology

[0004] 1) Insufficient number of synchronous sampling channels: In traditional ADC boards, due to the limited peripheral interfaces of the main control chip, there are generally only 8 to 32 analog-to-digital conversion channels;

[0005] 2) Insufficient data conversion capability: In order to reduce system power consumption, the traditional control system mainly adopts the FPGA (field programmable gate array) + MCU (microcontroller) scheme, and the FPGA is mainly responsible for the analog array after conditioning of the receiving transducer. The meta-domain signal is converted from analog to digital, and then the converted digital signal is transmitted to the MCU for processing and storage. Due to the weak signal processing capability of the MCU, the data conversion capability is insufficient.

[0006] 3) The synchronous control of multi-board cards is poor: when the traditional acquisition boards are cascaded, due to the delay of clock transmission, the phase consistency is poor when the working signal frequency is high

[0007] 4) The board has no preprocessing function: the traditional acquisition board has a single function, and can only package the original data and upload it to the upper system without preprocessing ability

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