Sim51

This software simulates the 8051 micro-controller on a PC. You can debug programs written for 8051 using this simulator. It displays the 8051 CPU registers (R0 to R7, Acc., PC, SP, DPTR etc.) on the screen. the same time watch selected memory locations (from Program Memory, External Data Memory, Internal Data Memory or SFR). you can also monitor the status of these peripherals. You can even simulate input to these peripherals. e.g. a key entry through 8279 can be simulated. Or you can change the input to any of the 8255 ports anytime.