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DS64MB201 aplication questions.

user3520686
Prodigy 130 points
Other Parts Discussed in Thread: DS64MB201

hi all:

I use two chips to driver 4 SSDs(SATAIII,6Gbps),Our SATA traces are less than 5-inch ,and via one IIC bus to configure the chips,IIC address are 0xa2 and 0xa4, Do you have any recommended settings to configure the registers(de-emphasis,equalization,and VOD and so on)?

  • 0
    Prodigy 130 points

    hi all：

    I think I have know how to set the registers,via set the gegisters,the system can know the SSDs,and can write

    data to SSDs and read from SSDs.

    But I have another problem: I must set the registers via system software,the download another system software which does not set all registers of DS64MB201. Only in this case,the system can work.

        If I download the system software which sets all the registers,the system can not know the 4 SSDs.

  • 0 in reply to user3520686
    TI__Mastermind 24975 points

    Hello user3520686,

    Just before the SMBUS Register Map on the datasheet for the DS64MB201, there is a section called “Recommended SMBUS Register Settings.” These are good guidelines for recommended settings when the total trace length is approximately 20 inches. Since your SATA traces are shorter, we have the following recommendations for these registers.

    De-emphasis (Registers 0x18, 0x26, 0x2E, 0x35, 0x3C, 0x43): These registers should be set to 0x01 which should be suitable for the trace lengths you mentioned.

    Equalization (Registers 0x0F, 0x16, 0x1D, 0x24, 0x2C, 0x3A): These registers should be set to 0x20, which is the default for the device. This will have the signal bypass EQ.

    VOD (Registers 0x17, 0x25, 0x2D, 0x34, 0x3B, 0x42): Set 1.0 Vp-p for these lanes by writing 0x0F to these registers.

    These recommendations are based on the assumption that the total loss is very low (< 10dB total loss). Do you know the total loss of your system?

     

    Additionally, I have a couple of questions regarding your second problem, as I am trying to better understand your issue.

    How are you writing to the registers of the device? You mentioned using the system software. What software is this? Also, if you write to the registers of the device, as long as you do not power-cycle the device, those register values will stay set to what you have written.

    Do I understand correctly that there are two different system software packages that you are using? How are you using these two software packages? Is one causing the other not to work properly?

    Best,

    Michael

    High Speed Datapath Solutions

    Analog Factory Applications

  • 0 in reply to Michael J Schultis
    Prodigy 130 points

    Hi Michael,

        Thanks for your recommendation.we use two steps(as mentioned) to  set the VOD\EQ\DE registers, system can write 4 SSDs and read from 4 SSDs normally.

        About second problem.we use the software embeded in FPGA(Xilinx K7-325T) to write the registers of the device,and the IIC bus is ok,because we have measured the IIC bus wave,meanwhile,we have read from the registers of the device.

        Yes,your understand is correct,we use two different system software packages.First,we download a system software and run,at this time,the registers of device have setted successfully,but the system can not know these SSDs;If I re-download another system software which doesnot write the registers,and run,the system can konw SSDs,and can write/read normally.I know I do not power-cycle,the values of registers are keeped.This is what I do not understand.

        Via IIC to set registers,if there are some special considerations?

        Thank you for your relay again!

        Best,

        vincent

  • 0 in reply to user3520686
    TI__Mastermind 24975 points

    Hello Vincent,

    Could you provide register dumps for the DS64MB201 device under the following conditions?

    1. When the SSDs are not recognized by the system
    2. When the SSDs are recognized by the system

    We would like to see if there are any changes in our device under these two circumstances to verify that the device is working as expected.

    Best,

    Michael

    High Speed Datapath Solutions

    Analog Factory Applications

  • 0 in reply to Michael J Schultis
    Prodigy 130 points

    Hi Michael,

     

    Before I posted this problem,I have done verification.when the SSDs are not/are recongnized by the system,

    the values of registers are the same exactly,and also are the same as expected.

    Are there special attentions when setting registers?or power up?or after setting registers,what shall we do ?etc

    Best!

    Vincent

  • 0 in reply to user3520686
    TI__Mastermind 24975 points

    Hello Vincent,

    There should not be any special considerations to take when setting the registers of the board. Once the registers are changed, the only event that would change the registers without you intentionally changing them would be power-cycling the device.

    When the device is powered down and then powered back up, the registers of the device will revert to a default set of registers which are noted by the “Default” column of the SMBus Register Map in the DS64MB201 datasheet. Any time the device powers down and then back up, you will have to reprogram the device in order for it to have the desired register settings.

    From your explanation, it seems as if our device is working as expected, as the device is in the same state when the SSDs are recognized as opposed to when the SSDs are not recognized. Is there anything else that is changing with our device between these two cases that would suggest our device is not working properly?

    Regards,

    Michael

    High Speed Datapath Solutions

    Analog Factory Applications

  • 0 in reply to Michael J Schultis
    Prodigy 130 points

    Hi Michael,

    So far,we do not fix this bug.As you say,we doubt that our system software has some bugs, and the system software is a debug version,so we will focus on fixing this bug in official version. And I will keep in touch with you.

     

    Best.

    vincent

  • 0 in reply to user3520686
    Prodigy 130 points

    Hi Michael,

    We have fixed this bug yestoday.It was our own problem,because our SATA IP of host does not support hot

    swap,so.....

    Thank you for your reply all the same.

    Best regards!

    Vincent