• State Resolved
  • Locked Locked
  • Replies 4 replies
  • Subscribers 32 subscribers
  • Views 1372 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.

DP83822I: Configuration of COMPTregister

g.f.
Guru 15510 points
Part Number: DP83822I

Hi,

I have questions about DP83822 Ethernet Compliance test of 100BASE-TX.

In DP83822, there are "Compliance Test Register(COMPT), address 0x0027".
I thought I need to configure this COMPT register, but in the following application report of DP83822,
there are no information about COMPT register.
********************************************************
DP83822 IEEE 802.3u Compliance and Debug
www.tij.co.jp/.../snla266.pdf
********************************************************

From above application report, it seems I only need to set following DP83822 registers
for 100BASE-TX Compliance Test:
- BMCR(Basic Mode Control Register), address 0x0000
- PHYCR(PHY Control Register), address 0x0019
- PHYRCR(PHY Reset Control Register), address 0x001F

Q1.Do I need to set COMPT register for 100BASE-TX compliance test?

Q2.If answer of Q1 is "yes", when and what value do I need to set to COMPT register?

Q3.If anwser of Q1 is "no" , what is the purpose of COMPT register?

best regards,
g.f.

  • 0
    TI__Mastermind 23675 points
    Hi g.f.,

    You are correct that all you need to do to configure the PHY for 100BASE-TX compliance are registers 0x0h, 0x19h and 0x1Fh.
    Please follow the compliance application note.

    The purpose of the COMPT register is mainly for 10BASE-T compliance testing.

    Best regards,
    Ross
  • 0 in reply to Ross Pimentel
    Guru 15510 points
    Hi Ross,

    Thank you for the reply.

    >The purpose of the COMPT register is mainly for 10BASE-T compliance testing.

    Let me ask about DP83822I COMPT register again.
    From description of COMPT register, it seem that COMPT register and
    DPDWN register bit[5], bit[4] need to be set up for 100Base-TX test.
    Doesn't COMPT and DPDWN need to be setup?

    By the way, in application report(DP83822 IEEE 802.3u Compliance and Debug),
    there are no information about setting COMPT register for 10Bas-T compliance test also.

    best regards,
    g.f.
  • 0 in reply to g.f.
    TI__Mastermind 23675 points
    Hi g.f.,

    The COMPT register is not needed for 100BASE-TX testing.
    All you need to use is register 0x0h and set it to 0x2100h.
    This will force the IDLE pattern that is required for 100BASE-TX testing.

    The reason why the COMPT register is not listed in the 10BASE-T compliance report app note is because it is not required with the other methods proposed within the document. There are multiple options, but the one in the app note is the most efficient.

    Kind regards,
    Ross
  • 0 in reply to Ross Pimentel
    Guru 15510 points
    Hi Ross,

    Thank you for the reply.
    I understood about the COMPT register of DP83822.

    best regards,
    g.f.