Tried to simulate PC_BIT Register using 16 DFFs (16 bit Register / Counter) for the ROM input addr in Tinkercad.
Although, luck was not on my side today. Probably my mistake was to do everything at once.
Considering 16 Bits take up a lot of gates for them which is impossible without many GATE ICs.
I will try it again but first simulating 1 bit at a time. Debugging this hot mess is impossible its more feasible to sart over.
Finally finished working on the Registers left i.e. flag register and instructions register.
Worked on the stack pointer (Count).
Finished FSM for the CPU. It’s using built-in ROM cause i’d die simulating ROM.
Finished decoder for the adder (for the ALU and FSM)
For the ROM programming I have used AI to speed up my work. Writing about 200 lines of hex codes, not my cup of tea.
Mul / Div parts are left, i’ll account for them later on. For now the FSM works.
Completed the ALU with instructions like ADD, SUB, OR, AND, NOT, XOR etc.
Fixed an error in the 8-Bit adder. The ALU is finally working.
Got started with registers. The previous register is done. 8 Bit register and a register file is made. Debugging in Logisim is VERY painful.
Architecture: Keeping 4 Registers (General Registers) Any 2 Accessible in one Clock pulse. Will start working on rest of the memory logic soon. Following integration of the ALU with Registers.
Very excited.
Got started on my CPU with Simulation first. Using Logisim. Making small components like D-Flip Flops, Registers, Half adders, Full adders and a 8-Bit binary adder.
Trying to make an ALU with 8 instructions for now using the 8-bit adder. Will think about multiplication / division later on.
Tried to make my own multiplexer logic for the operations but turn out to be more complex than I expected so Ill probably use builtin mux itself.
TODO: Lot of things are left, need to plan the whole architecture of the CPU. Probably going for a stack based arch but we’ll see.
Simulating in Logisim turned out to be more pain than I expected although I am a beginner in simulation software etc.
More updates soon.
