数字电压表的VHDL程序设计与硬件实现

摘要

Combining FPGA with ADC TLV571,a digital voltmeter was designed. The analog voltage measurement, analog-digital conversion,computing and reading were realized with VHDL language. TLV571,was controlled by FPGA with a state machine. The digital voltage and BCD codes of analog voltage are in one-to-one correspondence with theROM address and data. Using the look-up tables,the highest four bit BCD codes and the lowest four bit BCD codes can be read from corresponding ROM addresses and then the analog voltage can be computed through the addition operation of the two BCD codes. Experiments with experimental platform confirmed the validity of the digital voltmeter’s design.%将FPGA与模数转换器TLV571相结合设计了数字电压表。用VHDL语言编程实现了模拟电压的测量、模数转换、计算与读取，用状态机完成了FPGA对TLV571的控制。将数字电压、模拟电压的BCD码与ROM地址、数据一一对应，用查找表的方式从相应的ROM地址中取出高4位和低4位BCD码，对二者进行BCD码加法运算即可获得模拟电压值。通过实验平台测试验证了数字电压表设计的正确性。