Wot no SCLK using FT2232H

[NivagSwerdna]

This is driving me nuts...

A while ago I built a breakout board using FT2232HL-REEL and now I am trying to use it to read the ID from an SPI device

Nothing was working with the real device so I unhooked it and added my cheapo Logic Analyser to it and I see..



i.e. SCK seems to be missing... there is a CS and some data going out on MOSI but nothing on SCLK



According to the schematic SLK should come out of pin 16 but I am seeing a flat line

pin 17 and pin 19 (not wired on the schematic but shown on the logic analyser trace) are looking lively.

I check continuity and it looks like I am really observing pin 16

This has me stumped!  Why isn't my FT2232H sending a clock out on pin 16

PS
I am driving it via pyfdi on Win10.

[Ian.M]

Pin 16 of the FT2232H is TXD1 in UART mode, (UART channel A) so configure it as a pair of COM ports and send data to it on whichever one is channel A.   If neither port wiggles that pin, you've got a blown pin!  If it wiggles, there's probably a problem with your Python configuration code using pyftdi.

Sorry I've only got a CJMCU FT232H board here so I cant offer tested code or test your code.

[NivagSwerdna]

I like your thinking... I was in denial about having a faulty output...

Reset the drivers and configured as an output..

COM3... nothing on pin 16
COM4... nice wobbles on pin 38

Looks like that chip is heading towards the bin!  Shame they are super expensive and relatively hard to find now... at least I have a few spares.

Will report back when I have replaced it.

[NivagSwerdna]

Wow... well that pretty much wiped out a days work...

When I went to replace the FT2232H I was about to reflow and then on inspection under the microscope I saw that the gap between pins 15 and 16 wasn't quite as distinct as I would expect... I couldn't see a short it just looked a bit 'wrong'... reflowed the area around 16 and...



Thanks Ian.M, I needed that prod.