My customer has the following inquiries regards designing QN9080-SIP module
1. Chip select mode ISP does it needs to add an external pull-up?
2. There is a way to program the module via UART using ISP mode only (if yes, which pins are supported)
3. in case if the customer does not use the NFC front end what is the recommendation of these pins state (shall he need to leave these pins open or grounded)?
Waiting for your kind response, thanks in advance.
Solved! Go to Solution.
The QN908x supports the ISP function via the Flexcomm0 UART, Flexcomm3 SPI, or USB interface.
The pads are from PA14 to PA17 when using the UART/SPI for ISP. To enable the ISP mode, pull down the CHIP_MODE pin while the chip is reset. The chip is always in the ISP mode until the CHIP_MODE pin is pulled high. The ISP function starts when a valid handshake is received, and it starts to receive the binary file and program the flash with a new binary file.
The CHIP_MODE pin is pull-up-enabled by default. It is recommended to keep it floating when the ISP process is finished to avoid the IO current leakage.
Let me check and confirm about the Q3.