Why is simulator not equal to real life hardware?

I'm new to embeded C. I've got a Phytec Philips C552 chip and connected a LCD to it. I've made a simple prg to display char or string. Char works perfectly string brings only garbage. When I run the prg...
Speed difference between the target and the simulator

I'm trying to toggle an output pin but I have some timing differences between simulator and the target. The following code is reporting me a factor of two between the simulator speed and the target ...
Maybe this would be easier than real life ...

www.thinkgeek.com/.../
Measuring the real execution time

Hello, I would like to measure the execution time of a communication over the CAN bus between two Infineon XC16x boards. How can I do it with Keil, since the performance analyzer is available only in...
Difference between Simulated and real timings

I am using an AT89C53-24 microcontroller with a 12.000 MHz crystal. My program uses hardware timer (T1-Mode 1, interrupts enabled) to provide a 20 mSec heartbeat, and hardware timer (T0-Mode 1, interrupts...