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DS110DF410: CRC and port down/up will appear on corresponding ports at -25 degree

Part Number: DS110DF410

At room temperature, after successful chain construction, the signal is cooled down to low temperature. When the signal reaches -25℃, CRC and port down/up will appear on corresponding ports.

Structure: MAC<- >Re-timer<- > Port

In case of problems, by reading 0x27 and 0x28 , it is found that the eye height and eye width of the signal received by re-timer become small... However, when something goes wrong, the CDR of the corresponding port will be reset and can be back to normal.

My question:

1. What cause this effect, is there a temperature limit?

2. From which register that I could read the current status of CTLE?

Thanks.

  • Hi Tess,

    1). It may be because due to the temperature change CTlE settings may not be optimum. If you reset CDR at -25DegC does device recover?

    2). You can read register 0x03 to read CTLE settings.

    Regards,, Nasser

  • Hi Nasser,

    Thanks for your reply.

    1.The device could recover if I reset at -25 degree.

    2.I have read the 0X03 that the value is both 0x0 for normal and abnormal operation. 

    Is there any way that I could optimize and keep the CTLE setting ? Thanks.

    Best Regards,

    Tess

  • Hi,

    • Can you provide the value you observe for retimer channel register 0x03 when initializing the retimer room temp vs -25C?
    • Have you tried operating retimer in adapt mode 2 i.e. with DFE enabled? If the issue is eye opening margin reduction with temperature then the DFE should help. See below.

    Table: Enable the DFE, adapt mode 2

     

    STEP

    SHARED/CHANNEL REGISTER SET

    OPERATION

    REGISTER ADDRESS [HEX]

    REGISTER VALUE [HEX]

    WRITE MASK [HEX]

    COMMENT

     

    1

    2

    Channel

    Channel

    Write

    Write

    1E

    31

    00

    40

    08

    40

    Enable DFE (DFE_PD=0)

    Adapt Mode = 2

     

     Cordially,

    Rodrigo Natal

  • Hi Natal,

    1. The value 0x03 when initializing the re-timer room temp vs -25C are always 0x0.

    2. We have tried the DFE enable in mode 1/2/3, this cannot help with our issue.

    Question:

    1. Do you have any other suggestion for to solve this issue?

    2. We tried to manually set the CTLE, as the procedure below:

    To manually override the CTLE boost under all conditions, perform the following steps.

    1. Set the DS110DF410 channel adapt mode to 0 by writing 0x0 to bits 6:5 of channel register 0x31.

    2. Set the desired CTLE boost setting in register 0x3a. If the DS110DF410 loses lock and attempts to lock to a lower data rate, it will use this CTLE boost setting.

    3. Set the desired CTLE boost setting in register 0x03.

    4. Set the desired CTLE boost setting in register 0x40.

    5. If desired, set the CTLE stage 3 limiting bit, bit 2 of register 0x13.

     a. The manually CTLE could only work with mode 0? what's the procedure for mode 1/2/3 ?

     b. Why just set the 0x40 rather than 0x40-ox5f (table 11 in datasheet)?

     c.  When have the CTLE adaption Table 11 have the index from 0x40-0x5F, how does  the adaption works? The  value can be any value from the table 11, or it just give the range of adaption?

    Thanks for your help.

    Best regards,

    Tess

  • Hi,

    Your reported test results seem contradictory.

    • You mentioned that: "In case of problems, by reading 0x27 and 0x28 , it is found that the eye height and eye width of the signal received by re-timer become small... However, when something goes wrong, the CDR of the corresponding port will be reset and can be back to normal."
    • However you mention that 0x03 = 0x00 during all of your testing regardless of temperature that the retimer initializes at. It does not make sense to me that the retimer input eye opening values with the same CTLE setting would be different at a given operating temperature
    • Question #1: Can you please double confirm the value of channel register 0x03 for the cvase where  "eye height and eye width of the signal received by re-timer become small"
    • Question #2: Is it possible for you to measure the retimer temperature using a thermocouple for system ambient temperatures of -25C and room temp?

    Regards,

    Rodrigo Natal

    HSSC Applications Engineer

  • Hi Natal,

    • Question #1: Can you please double confirm the value of channel register 0x03 for the cvase where  "eye height and eye width of the signal received by re-timer become small"

             -The value of 0x03 really no change and is 0x03 even wen the eye become small

    • Question #2: Is it possible for you to measure the retimer temperature using a thermocouple for system ambient temperatures of -25C and room temp?

             - The surface temperature of re-timer for the -25C tmp  is about -5 to -7 degree.

    Best regards,

    Tess Chen

  • Hi,

    I've responded to you via direct email.

    Regards,

    Rodrigo