FTDI Community

General Category => Discussion - Hardware => Topic started by: Dr.Lightning on August 24, 2022, 02:31:39 PM

Title: Getting SPI to work on VNC2
Post by: Dr.Lightning on August 24, 2022, 02:31:39 PM
I'm getting conflicting information regarding the SPI on the VNC2 (32-pin).  Some doc suggests crazy 13 clocks/byte stuff.  Other doc suggests 8 clocks/byte as is normal.

Does anybody out there have DIRECT experience using the SPI on the VNC2?

Also, this Full Duplex / Half Duplex / Unmanaged mode stuff is "new".  It's NOT normal SPI.  Normal SPI is I guess what this FTDI VNC2 doc would call unmanaged.  It ***ought*** to be possible to simply exchange 8-bit words using 8 clock bits within a SS low period, and exchange an even multiple 8-bit words consecutively with an even multiple of 8 clocks within a single SS low period.  (Chip Datasheet: https://www.ftdichip.com/old2020/Support/Documents/DataSheets/ICs/DS_vinculum-II.pdf     Please See Figures 6.12, 6.3, 6.5, 6.6, 6.7 in that order!

Does anybody out there have DIRECT experience with this?

At this point I don't care at all what V2DAP or any other FTDI firmware does.  I want to know what the actual hardware does.  Does the actual hardware do the normal multiple-decades old SPI stuff, or was the chip hardware designer a bit messed up in the head, thus making their SPI incompatible with almost everything else out there?  (Sorry, my frustration is leaking out.)  It's a shame that only a single figure in the chip doc shows the actual SPI clock timing...

Thanks very much.