This issue is related to this thread I started about ISP in general - QN908X ISP HOWTO?. I am currently trying to figure out why my chip does not go into ISP USB mode.
I have a QN908C on a custom board. I am able to create an image in IAR an flash via jflash successfully. I can also take this image, create a legacy image and also successfully flash to my device in the same manner.
When I try to create a USB image however, jflash complains that:
- The CRC is incorrect
- The CRP function is not supported in the device type.
Neither of these appear to be an issue when the non-crp NXP QN9080C device is selected in jflash.
USB image is generated by the command
N908x_Image_Editor_v1.0.0.exe -i <file.bin> -u
JFlash generates its own CRC (red). The CRP register is unchanged from the default (0x0aa8ff).
I get these errors and the unit flashes successfully and my app runs but I am unable to get it to boot into ISP mode.
(Yes to CRC)
I tried again with the CRP enabled device. The image flashes but I lost the connection, I am unable to talk to it again via SWD. It also does not respond to the CHIP_MODE pin. After I attempted to flash, I noticed that the CRP bits are different:
I'm guessing that my devices are not recoverable at this point, right?
Why is the image different between the two devices and why is the Image editor not generating a valid CRC?