FTDI Community

General Category => Discussion - Hardware => Topic started by: Tycho on June 10, 2021, 12:12:10 PM

Title: FT232H SPI 30 MBaud wrong transmission
Post by: Tycho on June 10, 2021, 12:12:10 PM
Hi,

I'm getting wrong readout values if I increase the baud rate to 30 MBaud, see screenshots. I'm transmitting 0x1010 as MSB, CPOL=1, CPHA=0. At 5, 10 and 15 MBaud everything is ok, but at 30 MBaud, although the oscilloscope picture seems to be ok, there is a bit shift.

Are there any issues with FT232H SPI at high baud rates?

Thank you very much in advance!
Title: Re: FT232H SPI 30 MBaud wrong transmission
Post by: FTDI Community on June 11, 2021, 05:40:38 PM
Hello,

SPI modes 1 and 3 are not supported with our MPSSE engine.
If you require these modes, then you will need to consider FT4222H:

https://ftdichip.com/products/ft4222h/ (https://ftdichip.com/products/ft4222h/)

Best Regards,
FTDI Community
Title: Re: FT232H SPI 30 MBaud wrong transmission
Post by: Tycho on June 16, 2021, 12:19:16 PM
Quote from: FTDI Community on June 11, 2021, 05:40:38 PM
Hello,

SPI modes 1 and 3 are not supported with our MPSSE engine.
If you require these modes, then you will need to consider FT4222H:

Best Regards,
FTDI Community
Actually, CPOL=1, CPHA=0 is SPI mode 2.
Title: Re: FT232H SPI 30 MBaud wrong transmission
Post by: FTDI Community on June 18, 2021, 04:35:30 PM
Hello,

Yes that is correct:

ModeCPOLCPHANotes
000Supported
101Not Supported
210Supported
311Not Supported

We are not aware of any issues at higher speeds like 30 MBaud and the device is widely used.

What hardware are you using?

Are you using the D2XX drivers direct or using LibMPSSE library?

Maybe other FTDI Community users will be able to help you further on this issue.

Best Regards,
FTDI Community