EMC problem for using ESP-12F

[HungLI]

Dear all,

We are using ESP-12F for the wifi appliance design. As it is not enough GPIO pin for the application, we need to use SPI pin to control our LCD display with lower frequency. The firmware is almost done and product testing is ok in the performance but we found that there is failure in EMC regulation test EN55032 and a 40MHz clock for flash access is leakage from SPI pin. We try to change GPIO09/10 to simulate the software SPI with DIO flash control but 40MHz clock seems still to couple out from those pins. Does anybody suffer the similar problem before and give us some comments to solve this issue?