4位ALU设计，logisim，包含无符号加，无符号减，与，或-4 ALU design, logisim, plus contains an unsigned, unsigned subtraction, AND, OR

一位8421BCD编码的十进制数加减法器，电路具有进位、借位功能-A 8421BCD encoding decimal adder subtracter circuit has the function, carry out.

一种设计数字锁相环的思路，包含异或鉴相器、k模可逆计数器、脉冲加减计数器、N分频器等，实现相位的锁定。(A design of digital phase locked loop (PLL) consists of a phase discriminator, a K mode reversible counter, a pulse addition and subtraction counter, a N frequency divider and so on, to lock the pha

logisim设计 实现 加 减 与 或 异或 或非(Logisim design implements add and subtract and or exclusive or no)