What IDE is suggested to develop C8051F380 related product? Thanks.
you can use simplicity studio or silicon labs IDE. There is free keil license if you use these IDE.
other IDE like Keil uVision is also ok for C8051f380 software developing. driver is here Debug Driver for Keil µVision Software
The supported part need to be updated in the top part of the page:
what error you saw?
do you mind to upload the schematic of your F380 custom board?
how you connect the F380 and your UDA?
You should not put capacitor (to GND) on the RST/C2CK pin.
Try to remove that capacitor if you have and see if this change make any difference.