I can't find seria port at windows.

[Hokoshi]

I expected CDC's PORT to show up.

[abgelehnt]

There should be a blinking LED on the debugger if the USB connection is working and the firmware code is working properly.
If the debugger is working properly, you can see the COM port in the device manager. (WinUSB device and HID keyboard is also present)

[Hokoshi]

Hi Chi. P3.3 is litght on my board. Something is wrong. I will check again. Thank you for your valuable information. I'm glad you got a reply. It may be wrong for VCC to input 3V externally to my circuit. Very Thanks. 

[Hokoshi]

I think this solution
3V power supply operation is not supported.

I prepared another board and connected it to the 3V power supply and tried writing, but it was the same as when I connected it to the 5V power supply and then reconnected it to the 3V power supply, it stopped.

Certainly you share a circuit that operates on a 5V power supply, so I should have followed that.
disapoinnted.

Thanks.

[abgelehnt]

If using 3V power supply, the firmware code needs some changes:

1. Debug.H: #define FREQ_SYS 16000000
2. Debug.C: Uncomment this line GLOBAL_CFG = GLOBAL_CFG | bLDO3V3_OFF;//3.3V LDO OFF

[Hokoshi]

I don't have a commercial license for Keil.
I tried to Build with SDCC, but I couldn't do this.

Thanks.

[abgelehnt]

I have uploaded the 3v3 version of the firmware, you can try it out.

[Hokoshi]

Thanks for the 3.3V version firm. it was very helpful.

Serial port found(COM5). By the way, should I install the CMSIS-DAP V2 driver from somewhere normally?
I don't have time right now, so I'll try it when I have time.

In the future, I will try debugging and serial communication.

Thanks.

[abgelehnt]

CMSIS-DAP V2 driver will be installed automatically in Win10 or higher. If it is not installed automatically, you can manually install it as a WinUSB device.