• State Resolved
  • Locked Locked
  • Replies 4 replies
  • Subscribers 32 subscribers
  • Views 599 views
  • Users 0 members are here
Support feedback
Options
Options
Similar topics

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

DS32EL0421/0124 - Recommended Start-up Sequence

Hiroshi Katsunaga
Mastermind 6480 points
Other Parts Discussed in Thread: DS32EL0421, DS32EL0124

Hello,

My customer has a question about DS32EL0421 / DS32EL0124.

[Background]

They are going to use DS32EL0421 and DS32EL0124 as follows.

・A DS32EL0421 is directly connected to a DS32EL0124 with AC coupling. ---> RS=0 (Remote Sens enabled) and DC_B=0 (DC Balance enabled)

・They connect both with STP cable of the following length.

  (a) 5m

  (b) 10m

  (c) 15m

[Q]

Please tell me the appropriate start-up sequence of these devices.

It is helpful for understand it when you can explain it with the state diagram of the data sheet.

For example ...

(1-a) The 3.3V power supply for DS32EL0124 is powered up.

(1-b) The 3.3V power supply for DS32EL0421 is powered up.

(2-a) The 2.5V power supply for DS32EL0124 is powered up.

(2-b) The 2.5V power supply for DS32EL0421 is powered up.

(3) Set the Configuration pins for DS32EL0421 / DS32EL0124.

(4) Set the Configuration registor for DS32EL0421 / DS32EL0124. (Optional)

(5) Input TX data and TX clock

...  and so on ...

Best Regards,

Hiroshi Katsunaga

  • 0
    TI__Expert 3050 points
    Hi Katsunaga-san,

    Does your customer plan to use an FPGA or micro-controller for step 3 to set the configuration pins? Typically this pins are set with pull up or pull down resistors. If there is significant delay between power on of the 3.3/2.5 V rails and the setting of the configuration pins, the customer should toggle the reset pin to ensure that all of the desired settings are set.

    Overall, the power supply sequence and device configuration and data transmission sequences are OK.

    Mike Wolfe
    DPS APPS / SVA
  • 0 in reply to Mike Wolfe
    Mastermind 6480 points
    Hello Mike-san,

    Thank you for your fast response.
    I understood your comment.

    My understanding is as follows.
    <My understanding>
    ・The Control pins are read after POR. Therefore those pins must be set by pull up or pull down resistors.

    The start-up sequence of DS32EL0421 and DS32EL0124 is ...
    (1) Power up these devices (the 3.3V power supply before the 2.5V power supply)
    (These devices read the control pins after POR.)
    -> DS32EL0421/DS32EL0124 are IDLE state.
    (2) Set the configuration registers of these devices. (Optional)
    -> DS32EL0421/DS32EL0124 are IDLE state.
    (3) Input TX Data & TX Clock
    -> DS32EL0421 changes from IDLE state to LINK DETECT state.
    DS32EL0421 will transmit the some signal ?
    -> DS32EL0124 receives an input signal and the CDR will lock.
    DS32EL0124 changes from IDLE state to LINK DETECT state.
    DS32EL0124 will periodically send a link detect signal.
    -> DS32EL0421 detects DS32EL0124.
    DS32EL0421 changes from the LINK DETECT state to the LINK ACQUISITION state.
    DS32EL0421 will transmit the entire training pattern.
    -> DS32EL0124 detect that data coming in on the serial line.
    DS32EL0124 changes from the LINKDETECT state to the CLOCK ACQUISITION state.
    -> DS32EL0124 has successfully extracted the clock.
    DS32EL0124 changes from the CLOCK ACQUISITION state to LINK ACQUISITION state.
    -> DS32EL0421/0124 change from the LINK ACQUISITION state to the NORMAL state.

    Is my understanding correct ?

    Best Regards,
    Hiroshi Katsunaga
  • 0 in reply to Hiroshi Katsunaga
    TI__Expert 3050 points
    Hi Katsunaga-san,

    Yes, your understanding is correct. However, if the pins are controlled by a logic device like an FPGA, CPLD or MicroController, then you can use the reset pin on the DS32EL0421 or DS32EL0124 to make sure that the devices accept the configuration present on the pins.

    Mike Wolfe
    DPS APPS / SVA
  • 0 in reply to Mike Wolfe
    Mastermind 6480 points
    Hi Mike-san,

    Thank you for your response.
    I understood it.

    Thank you for your support.

    Best Regards,
    Hiroshi Katsunaga