Best on desktop

This simulator works on phones, but the memory tables and code stepping are much easier on a PC.

8051 Simulator

Assemble, inspect, and step through 8051 code with a cleaner workflow.

Originally forked from devanshshukla99/8051-Simulator, now maintained by Rohit K. Shaw.

🤖 AI Assistant (Groq)
Free AI Learning! Uses Groq API
  • Explain 8051 code
  • Step-by-step guidance
  • Answer questions
Register Value
A/PSW 0x00 0x00
B 0x00
SP 0x07
PC 0x0000
DPTR 0x0000
Flag Value
P
_UD
OV
RS0
RS1
F0
AC
CY
Register banks
00 01 10 11
R0 00 00 00 00
R1 00 00 00 00
R2 00 00 00 00
R3 00 00 00 00
R4 00 00 00 00
R5 00 00 00 00
R6 00 00 00 00
R7 00 00 00 00
RAM
0 1 2 3 4 5 6 7 8 9 A B C D E F
0x000 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
0x001 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
0x002 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
0x003 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
0x004 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
0x005 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
0x006 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
0x007 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
0x008 00 07 00 00 00 00 00 00 00 00 00 00 00 00 00 00
0x009 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
0x00a 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
0x00b 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
0x00c 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
0x00d 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
0x00e 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
0x00f 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
ROM
0 1 2 3 4 5 6 7 8 9 A B C D E F
0x000 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
0x001 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
0x002 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
0x003 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
0x004 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
0x005 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
0x006 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
0x007 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
0x008 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
0x009 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
0x00a 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
0x00b 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
0x00c 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
0x00d 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
0x00e 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
0x00f 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
Supported Opcodes
ADD AJMP ANL CJNE CLR CPL DA DEC DIV DJNZ INC JB JBC JC JMP JNB JNC JNZ JZ LJMP MOV MOVX MUL ORG ORL POP PUSH RL RLC RR RRC SETB SJMP SUBB SWAP