... I like your suggestions and these are things I have done in the past.(also done this...verify baud rate, connect scope to Tx pin and calculate the bit rate between HIGH/LOW transmission)

...Again all of this is fine and great. I think I have not been very clear on my initial post.

All these suggestions requires tools. Yes, I have them. Yes, I use them.

However, your feedback "assumes" that I have configured the Crossbar correctly and know where the TX Clock is going to be located. Or even turned on, for that matter. Perhaps, I did not "Enable" the crossbar. In that case, hooking up the scope does me no good!

The simulator clearly displays the results of the Crossbar and what was written to it. It clearly states "Enable/Disable" status.

Am I the only person that has ever written code that I thought was correct, only to find out later that I did not understand the data sheet?

Again, imagine this assumption.... I believe the correct value to write to the crossbar to enable it is "XYZ". Now I run the Hardware Debugger, have my scope connected to P0.4 TX and I see NO signal. I look at my code and say, "Yes, I wrote "XYZ" to the crossbar, it should be enabled.. I can't imagine know what is wrong...?" I would be stuck here forever!

The Keil Simulator cleary shows that the Crossbar is NOT enabled. Now it's up to me to re-read the data sheet to figure out the CORRECT value to write to it.

How will connecting a Scope and writting "UU" tell me if the crossbar is "Enabled"?

Does this make sense to anyone besides just me?

I am not saying the simulator is better than real hardware debugging. I am simply saying that the Simulator can be very useful and present information that the hardware debugger can not without hardware tools, scope, etc.

Comments/concerns/solutions are all welcome.