How to connect a signal from RocketCore class to FPGA chip class

Hi everyone, I am a newbie in Chisel.

My goal is to add a instruction detecting signal (in particular the DIVISION instruction) to the rocket class of the Rocket Core module of the freedom repository. I want to connect it to one of pin of JA on board Arty 35T to check that if I detect successfully while the chip is running on a FPGA.

I want connect the signal from RocketCore -> RocketTile -> RocketSubsystem -> System -> Platform -> FPGAchip, but I am troubled with the inheritance syntax in Chisel.

Does anyone has experience in that case, please help me or discuss some troubles with me in details
Thank you so much for any kind helps.