/TD4-4BIT-CPU

simple 4-BIT CPU with 74-serials chip

Primary LanguageHTMLBSD 3-Clause "New" or "Revised" LicenseBSD-3-Clause

TD4

#LOAD0 = D6 | D7
#LOAD1 = #D6 | D7
#LOAD2 = #(#D6 & D7)
#LOAD3 = #(D6 & D7 & (#C | D4))
SEL_A = D4 | D7
SEL_B = D5

A. 先焊接尺寸小,低的元器件,再焊接高的元器件,推荐焊接顺序如下:
1. 发光LED,二极管1N4148,直插电阻,USB接口。
2. IC插座
3. 8位拨码开关、4位拨码开关
4. 按键开关,电解电容,拨动开关

B. 注意芯片插座,8位拨码开关和4位拨码开关的焊接方向

架构

  1. RAM
  2. 4bit -> 8bit
  3. ALU
  4. 中断

指令

  1. 算术逻辑指令
  2. 寻址方式(立即数寻址、相对寻址、寄存器寻址等)
  3. call push pop

reference0:
指令格式
TD4套件

reference1:
https://hackaday.io/project/8442-ttl-based-4-bit-cpu
https://hackaday.io/project/26215-td4-cpu
http://kamakurium.com/wp-content/uploads/2016/01/cpu_td4
http://visual6502.org/
http://www.4004.com/