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本超声波测距仪设计中采用的是MAX7000s系列中的EPM7128SLC84-15的CPLD器件，其最高频率可达175.4MHz，可用于组合逻辑电路、时序逻辑电路、算法、双端口RAM等的设计。充分利用了其多达128个宏单元、68pin可编程I/O口，使该器件可以将分频功能、计数功能、显示编码功能、振荡功能全部集于一体。又因其延时平均的特点，保证了测距结果精度高、响应速度快。
关键词: 可编程逻辑器件 超声波 测距
Abstract: Generally speaking, the ultrasonic range finder can be used to measure the object position and liquid level, it is suited to measure the height of building’s internal and water line. My device make use of CPLD(Complex Programmable Logic Device) and uses VHDL(Very High Speed Integrated Circuit Hardware Description Language) to program. Utilizing the software of MAX Plus II to carry out the simulation and debug.
The design of the ultrasonic range finder applies the EPM7128SLC84-15 appliance .The highest working frequency is up to 175.4MHz and it is belong to the MAX7000S devices series. The EPM7128SLC84-15 can realize the design of the compounding logic circuit, sequential logic circuit, calculation, double ports-settings RAM and the like. To make use of the EPM7128SLC84-15 with up to 128 macro cells that are combined into of 16 macrocells groups and 68 maximum user I/O pins, the device has comprised frequency divider, counter function block, display function and oscillator. Ensure the high measurement precision and quick respond due to the EPM7128SLC84-15’s average pin-to-pin logic delays.ousing Resource Archives System (HRAS) is suitable for filing housing resource related file. Through the system, users can input, audit and manage housing resource files. More important, one could easily translate the original hardcopy to electronic record file via scanning system and save to the HPMS system for browsing future or develop for other potential usage; HPMS does not only have a very strong engine to support housing property file input, browse, review and management, but has extendable and general feature.
This paper introduces the detail of main function development and describes the development process of sub management system.
Keyword: CPLD, VHDL, Ultrasonic wave, Distance measurement