Steps to Implement Online Debugging with KEIL

In addition to writing, compiling and simulating execution to debug user programs, Keil can also implement online debugging through the serial port, that is, to see the execution effect of the code on the hardware through single step and breakpoint. The steps are as follows:

The AT89C51CC03 microcontroller is used, and the keil version is Keil C51 V9.00.

1. Use KEIL to create project files, program, compile and debug user programs to ensure that there are no problems in software execution.

2. Modify the configuration file config.inc in the keil/c51/FlashMon directory of the KEIL installation point that is consistent with the microcontroller model. Mainly modify the two parameter values ​​of cpu_clock and code_start according to the actual situation. I changed them to 12M and 0E000H.

3. Recompile the programs in this directory and generate a new debugging program Monitor.HEX. If it is not regenerated, check the option create HEX file.

4. Run the FLIP program and burn Monitor.HEX into the MCU. The starting address is 0E000H, that is, SBV=E0, BLJB is selected, BSB=0, EB=FF

5. Click the Start Application button to execute the Monitor.HEX program

6. Run Keil, open the project file, modify the debugging parameters, that is, menu project-->option for target, select debug page, click use Keil monitor 51 driver on the right, click the setting button, select the serial port and baud rate, note that it should be consistent with the baud rate used when burning the chip, generally 9600. It should be noted that if the serial port is in automatic mode (that is, in addition to the three communication lines, RTS and DTR are also connected), RTS and DTR need to be set to inactive.

7. After compiling the program, click the debug command under the debug menu. You can execute it step by step, set breakpoints, and run it at full speed. At this time, you can actually use the microcontroller hardware to run the program and see the execution effect, such as display, key response, etc. In this case, you can debug the actual execution effect of the program.

8. If you do not set breakpoints and run the user program at full speed, the user program will be consistent with the actual operation, Keil will lose control of the user program and will not be able to interrupt the execution of the user program (only pressing reset can interrupt the user program)

9. If you find a problem, you can exit the debugging state, modify the program, recompile, and then enter the debugging state again, and debug by single-step or setting breakpoints. Note that you cannot interrupt when running at full speed, otherwise you will not be able to exit (the consequence of forced exit is that the monitor state is incorrect and you cannot enter the online debugging state again).

10. After exiting debugging, the monitor program cannot be executed again, whether you press reset or flip the program's start application button. At this time, the user program is executed. If you want to continue debugging, you can only erase the flash and burn the monitor into the microcontroller again.