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DS80PCI800 / 2.5Gbps and 5.0Gbps sRIO data rates

Toshiyuki
Mastermind 7075 points
Other Parts Discussed in Thread: DS80PCI800

Hi,

We would like to equalize 2.5Gbps and 5.0Gbps sRIO data rates with DS80PCI800.

Could the different data rates be input the adjacent channel of DS80PCI800 ?

Best Regards,

Kato

  • 0
    TI__Mastermind 43795 points

    Hi Kato,

    Yes, different rates can be applied to individual channels.  I would suggest using the DS80PCi800 settings below to enable the terminations all the time and utilize a "limiting" output buffer style which is consistent with SRIO at the 2.5 and 5G data rates.

    RATE: 1K resistor to GND

    RXDET: 1K resistor to VIN(3.3V operation) or VDD(2.5V operation)

    Regards,

    Lee

  • 0 in reply to Lee Sledjeski
    Mastermind 7075 points

    Hello Lee -san,

    Thank you for the reply. Are there any problems if RXDET is left floating ?

    Best Regards,

    Kato

  • 0 in reply to Toshiyuki
    TI__Mastermind 43795 points
    Hi Kato-san,
    RXDET is designed specifically for PCIe. It is a cleaner solution to tie it high and leave the termination enabled as soon as the PCI800 powers up. It is more in line with the SRIO expectation.
    Regards,Lee
  • 0 in reply to Lee Sledjeski
    Mastermind 7075 points

    Hi Lee-san,

    I understood what we should do for SRIO.

    Thank you very much for your cooperation and patient.

    Best Regards,

    Kato

     

  • 0 in reply to Toshiyuki
    Mastermind 7075 points

    Hi Lee - san,

    Customer will use DS80PCI800 in SMBus Slave Mode.

    Would you please provide the recommended register settings ?

    Best Regards,

    Kato

  • 0 in reply to Toshiyuki
    TI__Mastermind 43795 points

    Hi Kato-san,

    To set the DS80PCI800 up for this application here are the pin and register settings.  The setting on several of the pins will be dependent upon the Supply voltage mode.  When Vin = 3.3V, the control pins are referenced to the higher 3.3V level.  When VDD = 2.5V is supplied directly to the DS80PCI800, the control pin logical high is referenced to the lower 2.5V level.

    Pin Connections:

    ENSMB = 1K pullup

    SCL/SDA = 2K pullup on SMBus

    AD[0-3] = SMBus Address

    SD_TH = Float

    EQA[0-1] = Float

    RATE = 1K to GND

    RXDET = 1K pullup

    VDD_SEL = Float/ tie to GND depending on 2.5V or 3.3V supply mode of operation required.

    VIN and VDD = According to desired supply mode.

     

    Registers:

    0x06 = 18'h (Enable SMBus register control)

    0x0F, 0x16, 0x1D, 0x24, 0x2C, 0x33, 0x3A, 0x41 = 00'h  (EQ setting (minimum))

    0x10, 0x17, 0x1E, 0x25, 0x2D, 0x34, 0x3B, 0x42 = AB'h (VOD setting (1000mV))

    0x11, 0x18, 0x1F, 0x26, 0x2E, 0x35, 0x3C, 0x43 = 01'h (DEM setting (-1.5 dB))

     

    Regards,

    Lee

  • 0 in reply to Lee Sledjeski
    Mastermind 7075 points

    Hi Lee - san,

    Thank you for the reply.

    Additionally, if we set Manual RX-Detect, input is 50Ω, should we write 0x0E[3:2]=11 ?

    Best Regards,

    Kato

  • 0 in reply to Toshiyuki
    TI__Mastermind 43795 points

    Hi Kato-san,

    The Rx-Detect function will be taken care of with the pin setting of RXDET=1.  To control RXDET function with SMBus registers, it is necessary to write the override register bit as well.  Here is an example using 0x0E

    Register Write 0x06 = 18'h  //* Enables SMBus registers

    Register Write 0x08[3] = 1'b  //* Override RXDET pin and use SMBus Register setting

    Register Write 0x0E[3:2] = 11'b  //* Set termination to "on" for CH0  - To change all channels, 7 additional registers will need to be changed as well

    Regards,

    Lee