Please let me know the following details:
1. Are you using a custom board?
2. Which firmware are you using for testing?
3. Please elaborate the following statement:
"Some products are normal at first,and then have problem after use"
By this, do you mean to say that the device initially enumerates as Bootloader device and later on is lost when you download the firmware to RAM? Or is it like the device re-enumerates after downloading the firmware but lost after certain amount of data transfers?
4. Which OS are you using?
1.No,but we are based on the public board to design.
2.I'm using code example:"cyfxusbspiregmode".
3.No,I normally used it these days, it may be broken next week.
The Problem is CYUSB3014-BZXI can't be recognized in PC.Is it caused by a connection problem?
According to my understanding, you are using a custom board that is designed based on a development kit. When the board is plugged in, it always enumerates as USB Bootloader device. Also the board works well sometimes but it fails sometimes. Please correct me if Iam wrong.
Also, please confirm that you are using the default SDK example cyfxusbspiregmode without any modifications.
This can be caused due to a hardware or a firmware issue. To isolate the issue, please share the UART debug logs when the device is lost.