4 Replies Latest reply on Jan 8, 2020 5:19 AM by StSa_4592716

    Bit Banged SPI Speed


      I have a project where I need to read in 12 SPI ADCs simultaneously using a common MOSI, SCLK, and CS. Therefor I need to bit-bang the SPI. I was looking at cyfxusbspiregmode as an example, but when I run it on the EZ-USB FX3, it seems very slow, with about a 6usec clock cycle. There are two 1usec delays, which, when removed, gets it down to 4usec. Adding the define to use direct register mode, gets it down to 3 usecs. This still seems really slow, given a processor clock of 200MHz. I'm just getting started with this device, so maybe I'm missing something basic. I've bit-banged SPI on the Teensy with speeds in the MHz.