MICROPROCESSORS

CPU Simulator

8-bit educational CPU
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02 / CPU & RAM

Ready
Separate memory and CPU blocksMemory on the left contains separate program and data stores. On the right, the CPU contains its control unit, registers and ALU. Labeled arrows show instruction, address, read and write transfers. MEMORYSeparate program and data stores CPU8-BIT PROCESSOR Program addressInstruction → Data address Read data → ← Write data PROGRAM MEMORYCurrent instruction—Up to 256 instruction slots RAM256 × 8-bit dataADDRESSVALUE 000010020030040050060070PC · PROGRAM COUNTER0IR · INSTRUCTION—MAR: —OPERAND LATCH—MDR: —CONTROL UNITREADYACC · ACCUMULATOR0STATUS FLAGSZ 0 · N 0 · C 0ALU—OUTPUT PORT—MAR · Memory address registerMDR · Memory data registerRegisters · Control · Arithmetic & logic
1 FETCH2 DECODE3 OPERAND4 EXECUTE5 WRITE BACK
Assemble a program, then use Micro-step to follow each transfer.
Instructions0Micro-steps0ACC binary00000000ACC signed0

03 / Data memory

Select a cell to inspect or edit it while paused at an instruction boundary.

Address 0

04 / Input & output

IN consumes queued bytes (0–255). OUT prints ACC.

Input queue: empty

No output yet.

Execution trace

Waiting for the first instruction.