A computer made completely out of logic gates. Version 2. V1 can be found here: https://circuitverse.org/users/13948/projects/49969
Because of the limitations of the circuitverse.org simulator, and for easier use, some inbuilt components are used (like the 256-byte RAM module), but most of it is made up of OR, AND, NOT, XOR, NOR and NAND.
This project was originally made for my profile project. This is (or will be) version 2 of the 8-bit computer.
Working CPU with eight 8-bit registers and eleven commands. Instructions in the project, command list below.
LDA r - loads value from register r into accumulator
STA r - stores accumulator value in register r
CLR r - clears register r
INC r - increments the value of register r and replaces into r
DEC r - decrements the value of register r and replaces into r
COM r - stores the complement of the value in register r in the accumulator
ADD r - adds value in register r to the accumulator
SUB r - subtracts accumulator value from value in register r, replaces into accumulator
AND r - stores value of (accumulator AND r) in accumulator
IOR r - stores value of (accumulator OR r) in accumulator [inclusive or]
XOR r - stores value of (accumulator XOR r) in accumulator [exclusive or]
*Eight 8-bit registers: r must be a value between 0 and 7 and refers to the address of the register, not its contents*
This is a CPU witch is capable of executing a lot of stuff in one clock cycle, and this CPU can shift left up to 7 times and shift right up to 7 times witch means that it is possible to multiply and divide in one clock cycle if you program a table in the program memory. it has a 32 bit instruction width and a 8 bit address. it also has
The ALU has the following operations:
This is an example implementation of the uCISC instruction set as defined at https://github.com/grokthis/ucisc. So far it implements the Copy and ALU instructions. Note that multiplication, division and floating point ALU operations are not currently supported. This processor is enough to execute real programs.
The EEPROM is programmed with the fibonacci calculation found in the uCISC examples.