Basically my question is regarding maximum length of SPI routing, and route efficiently in my scenario and any timing issues(Setup and Hold).
I am just explaining my scenario. Please bear with me, it is very big message...
I have an EVK which has SPI exposed to a 10-pin connector, and I have slave board (RF board) which has SPI exposed to 20-pin connector.they can't be directly connected, that's why I am designing a 10-pin to 20-pin interfacing board to interface effectively.
Unfortunately because of mechanical constraints, i need to use a flex cable to route between 10-pin Connector on EVK to 20-pin interfacing board. Slave board directly mates to 20-pin connector of interfacing board.
I am running SPI at max 8Mhz with 4-20nS Rise times.
I don't have any control on Slave board and EVK side. Only i have control on 10-pin to 20-pin interfacing board.
I want to know what is the maximum length of flex cable can used between EVK and interfacing board.
What things can be done to mitigate SI problems and ensure signal quality. Is there any free tool (I have altium using which i am not able to simulate) to simulate this scenario. Is there any timing issues that need to be taken care of here.*
I want more of a quantitative explanation.