SPI MISO Pin Unused

[jimmykk]

Hi

I am using FT232 Chip and interfacing it with several MUXes ADG725 using SPI Protocol. The Slave Select pin is sent to a Decoder to select slaves as required.
The MUX only needs CLK and MOSI from FT232 for communicaiton. That is MISO Pin is unused.
So the question is leaving the MISO pin unconnected will effect proper communiation of SPI or should it be pulled down/up?

 

[spudboy488]

If you are not reading back a SPI value, it should be terminated like any other unused input. If you are creating a PCB, I would suggest adding a pull-up that could be removed if you ever wanted to wire in a read function in the future.