Why local variables values are displayed as ?

Why am I not seeing the values of the local variables?

Quite likely for exactly the reason the tools already told you about: because at a given point in time, many of those variables simply don't exist. Local automatic variables only exists while the code block they're in, i.e. their "scope", is being executed.

Why am I not seeing the values of the local variables?

Quite likely for exactly the reason the tools already told you about: because at a given point in time, many of those variables simply don't exist. Local automatic variables only exists while the code block they're in, i.e. their "scope", is being executed.

I'm in the main() code block. In this block, some of the local variables I have are as follows:

unsigned char index;
bool isAorB;

while main is executing, values of all local variables are <not in scope>

The application I'm executing under control of debugger does not have operating system.

main() code block

I do not know what a "code block" is

you need to be in the main function to see variables local to main()

Erik

I am in the main function. When I'm in other functions, their location variables values are not shown in debugger either.

Every time you enter the debugging mode, you need to add the Local Variables into the watch window.

Local variables were already in Watch and Call Stack windows but I still added them after entering debug mode. No difference, still <not in scope>.

Just to make sure, do I enter debug mode by toggling Ctrl + F5, am I correct ?

I'm using Keil micorVision V4.71.2.0

The Keil Project I'm using was created with older version of Keil. My colleague suggested that I re-create project with latest version of Keil.