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ADC34J44EVM: ADC34J44: SPI coomunication problems

Lorant Bugar
Prodigy 50 points
Part Number: ADC34J44EVM
Other Parts Discussed in Thread: ADC34J44, AM3357

Hi, 

I bought ADC34J44EVM and tried with ADC3000 GIU application configure chip ADC34J44. I added ti SPI pinheader logic analyser. I tried write register 0x02 to 0x02 and register 0x03 to 0x02. 

It is work fine. See screenshot 1: Data is 0x40 0x02 0x02  ...(Dosn`t understand why change clock duty but okey, its work). I see in image CPOL = 0, because SCLK start from LOW. CPHA is 0 because data is on Rising edge clock. I tried read data in GUI it is wroted good. 

I have AM3357 with linux and tried write to same data on SPI but register dosn` set. On EVM removed pinheader jumpers. To ADC_SDENB connected CS pin, ADC_SCLK  to  Clock, ADC_SDIO(SDATA) to MOSI, ADC_SDO(SDOUT) to MISO

Screenshot from communication AM3357 <--> ADC34J44

Read:

ADC34J44 dosn`t answere, and I controleled in GUI after write process but dosn`t set registers.

Please help, What Did I Do Wrong?

  • 0
    TI__Guru* 91947 points

    Lorant,

    Make sure the Vih is 1.2V minimum and Vil is 0.4V max for all of these SPI signals. You must also do either a hardware or software reset before attempting any SPI transactions. Make sure SCLK is no greater than 20MHz.

    Regards,

    Jim

  • 0 in reply to jim s
    Prodigy 50 points

    Hi,

    I use Sitara AM3357, it have 3v3 logic. In datasheet is wroted all SPI IO supported 3V3 logic. I reseted HW with pushbutton on EVK. SCLK have 1 MHz, I tried greater and slower too. Dosn`t work.

    I tried communicate across FMC connector too. I JP8 Jumper added from USB to FMC and JP2, JP3, JP4, JP5 jumpers I returned. But to same . 

     

    thank you

  • 0 in reply to Lorant Bugar
    TI__Guru* 91947 points

    Lorant,

    I would suggest you place the jumpers back on, verify the GUI can still write and read properly, then take a scope probe and monitor each signal to see how the SPI is actually operating wit the GUI. This may show you something you are not doing correctly.

    Regards,

    Jim

  • 0 in reply to jim s
    Prodigy 50 points

    Jim,

    in first post i wroted, with gui works good, first screenshot is writing sequence With gui over altera <-> ADC.

    thank you,

    regards,

    Lorant

  • 0 in reply to Lorant Bugar
    TI__Guru* 91947 points

    Lorant,

    Not sure what you are saying. The GUI uses a FTDI device, not Altera device. No matter what, your screen shots of the SPI appear to be from a signal tap or chipscope like tool used by the AM3357. I am suggesting using a scope to see what the signal levels really look like. 

    Regards,

    Jim

  • 0 in reply to jim s
    Prodigy 50 points

    Jim,

    I`m sorry if I explained it in a wrong way. I downloaded schematic for ADC34J44EVB. See the attachment. According to the schematic I think GUI communicates with Altera (5M80ZT100) over FT245RL. To altera is connected ADC SPI and LMK SPI. I looked ADC32JXX schematic there it is as you wrote "GUI uses only a FTDI device" but in ADC34J is not .  

    Thank you, Tomorrow I upload screenshots from scope 

    regards,

    Lorant

  • 0 in reply to Lorant Bugar
    TI__Guru* 91947 points

    Lorant,

    Sorry about the last reply. You are correct. Some of our EVM's have this CPLD and some don't. I thought this one did not.

    One test you can do I just thought of was to do to SPI writes only in case there is an issue with the SPI read. In this test, you would use a power supply that you can monitor the current used by the ADC EVM. After the board is turned on and clocks are present, do a SPI write to power down the device and see if the current drops on the supply.

    Regards,

    Jim

  • 0 in reply to jim s
    Prodigy 50 points

    Hi Jim, 

    In attachment I add screenshots from scope:

    Write with GUI :

    Write with Sitara: 

    Read with GUI :

    Read with Sitara :

  • 0 in reply to Lorant Bugar
    TI__Guru* 91947 points

    Lorant,

    Please try writing a 0x04 to address 0x15 and see if you notice the current dropping going to the EVM. This enables the global power down.

    Regards,

    Jim