This is an Arduino code to program EEPROMs (microcode instructions programmer) for a breadboard 8-Bit CPU inspired by Ben Eater's CPU design https://eater.net/8bit
CPU Features include:
- Reduced components in compare with Ben Eater's design
- 512 bytes of SRAM (256 addresses producing 2 bytes of data per address) instead of 16 bytes (16 addresses and 1 byte of data)
- 4 CPU cycles per instruction instead of 6
- Separated 16bit ram bus for instructions and data (8 bits for instructions + 8 bits for data)
To program the EEPROM, you will need the following:
- An Arduino compatible board
- 2 shift registers (e.g. 74hc595)
- Of course, the EEPROM chips
| Clock Module | Program Counter | Input Switcher | Ram Module | Logic Control | Registers Module (A&B) | ALU Module | Display Module | Input Module |
|---|---|---|---|---|---|---|---|---|
| 2x 555 Timer | 2x Binary Counter (SN74HC161N) | 4x 2to1 data selector (SN74HC157N) | 4x 4K-RAM (CY7C168A) | Binary Counter (SN74HC161N) | Quad AND (SN74HC08N) | 2x Binary Adder (CD74HC283E) | 555 Timer | Octal D-Type Flip-Flop (CD74HC273E) |
| Tactile Button | 8x Led | 3-State Transceiver (SN74HC245N) | 3-State Transceiver (SN74HC245N) | 2x EEPROM (AT28C64B-15PU) | 2x 3-State Transceiver (SN74HC245N) | 2x Quad XOR (SN74HC86N) | Binary Counter (SN74HC161N) | Hex Inverter (SN74HC04) |
| Switch (double throw) | 3-State Transceiver (SN74HC245N) | Octal D-Type Flip-Flop (CD74HC273E) | Switch (double throw) | 16x Led | 2x Octal D-Type Flip-Flop (CD74HC273E) | 3-State Transceiver (SN74HC245N) | Dual 2-to-4 Line Decoder (CD74HC139E) | Tactile Button |
| Quad NAND (SN74HCT00N) | EEPROM (AT28C64B-15PU) | 3x 8-DIP Switch | ||||||
| Hex Inverter (SN74HC04) | 4x 7-seg display |
