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jg_spitfire
Adventurer
Adventurer
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Registered: ‎12-10-2019

Wrong voltage in SPI MOSI pin - myir zturn board zynq 7020

Hi, I am doing an SPI test with the myir board zynq7020 and when I connect the oscilloscope I see my CLK signal at 3.3V approx (yellow signal) but the MOSI pin is 4.8V (purple signal), I don´t have any other hardware connected to the board I just measuring the pins I have configured as SPI, maybe I am missing some config?, thanks, the CLK signal is at 20MHz

pinout_spi_adf5902.jpgspi_adf5902 overvoltage.jpg

block diagram adf spi.jpg

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bruce_karaffa
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Scholar
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Registered: ‎06-21-2017

What voltage is powering the device the SPI is connected to?  Is the MOSI pin pulled up to 5V on the schematic?  Are your scope probes grounded?  What is the bandwidth of your scope and probes? 

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jg_spitfire
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Registered: ‎12-10-2019

@bruce_karaffa 

What voltage is powering the device the SPI is connected to?

"I don´t have any other hardware connected to the board I am just measuring the pins I have configured as SPI", I am measuring directly pin Y9 (MOSI)  and T9 (clk)

 

Is the MOSI pin pulled up to 5V on the schematic?

no, this is the board schematic

fpga mosi pin.jpg

Are your scope probes grounded?

yes

 

What is the bandwidth of your scope and probes?

300MHz

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MattC1
Visitor
Visitor
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Registered: ‎09-10-2020

Did you get the SPI working on the zturn board? I've been trying by connecting SPI directly to MIO or routing to EMIO and always get connection timed out errors.

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