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General Category => Discussion - Hardware => Topic started by: Siddharth Mishra on September 28, 2021, 03:37:36 PM

Title: Getting Incorrect Data on the Slave over SPI via FTDi (FT2232H)
Post by: Siddharth Mishra on September 28, 2021, 03:37:36 PM
Hi Team,

We are using SPI Interface with FT2232H Chip with the Chip being the Master and the MCU (KS20 Family of MCU by NXP) acting as slave. When we transmit the data "15" in decimals from the FT chip, then at the Slave side i.e. MCU side we are receiving the data as "7" which supposedly should be "15" but when we connect 10K Pull-Up Resistor on the SCK Line, we are getting the appropriate data of what is being sent.

Do we really need to connect that Pull-up resistor ?  or is there any other Configs or changes that are needed?

Title: Re: Getting Incorrect Data on the Slave over SPI via FTDi (FT2232H)
Post by: FTDI Community on September 29, 2021, 12:53:24 PM
Hello,

The SCK line should normally be a push-pull output on this device (unless your code switches the pin to input mode at any time)

What I/O voltage does your MCU use? Is it a 3v3 I/O

We would recommend to check with a scope or logic analyser with analog capability to see what the waveforms are doing,

Best Regards, FTDI Community