4.移位相加式十进制硬件乘法器电路， 要求：输入两个1位十进制数，利用移位相加法计算它们的乘积，显示乘数、被乘数和积。-The shift and add type decimal hardware multiplier circuit, Requirements: Enter both a decimal number, and calculate their product using a shift-add method, display multiplier, multiplic