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DP83869HM: LED configuration

Part Number: DP83869HM

Dear Team, 

My customer are using DP83869HM to replace comptitor(Broadcom, BCM5482S) so they want to same LED configuration with competitor

Current schematic ,setting and LED action are like below. 

Register setting 

0x18 = 0x6B00

0x19 = 0x4040

0x1A = 0x0002

<Result>

Link down :LED_2 turn on

Link up + No TX/RX : LED_2 turn off

Link up + TX/RX activity : LED_2 blink

But they want to use below configuration. Is it possible to act like below? the competitor device, BCM5482S can support below configuration. 

If possible, please let me know regarding register setting, How can I set register value? 0x18, 0x19, 0x1A??

Link down :LED_2 turn off

Link up + No TX/RX : LED_2 turn off

Link up + TX/RX activity : LED_2 blink

Please review above request and let me know your opinion. 

Thank you. 

  • Hi Nam,

    Let me check with the team. Due to U.S. holiday, I will get back to you next week.

    Thanks,

    David

  • Hello David, 

    Is there any update on this request? 

    We are trying to test for the desired LED_2 operation. The customer set the register to implement the desired LED_2 operation.  

    0x19(LEDS_CFG2) = 0x4440

    0x18(LEDS_CFG1) = 0x6100 (0x18, LED_2_SEL = 1h) 

    0x1A(LEDS_CFG3) = 0x0000 (LEDS_BLINK_RATE=50ms)

    <The desired LED_2 operation> 

    1. Link down :LED_2 turn off

    2. Link up + No TX/RX : LED_2 turn off

    3. Link up + TX/RX activity : LED_2 blink

    Action 1 and 2 is ok. But The LED seems to blink when the TX/RX signal frequency is slow, but it always appears to be on when the data is fast. 

    Please review below questions and let me know your opinion. 

    1. What is the LED turn-on time when there is a TX/RX signal under (0x18, LED_2_SEL = 1h) condition? 

    2. Can this time be set to less than 50 ms?

    3. Is there other way to implement the desired LED_2 operation? 

    Thank you. 

  • Hi Nam,

    The only options for LED selection are shown in register 0x18. If LED_2_SEL = 1h, the light will turn on if there is activity, not blink. This is why you are seeing always on when the data is fast but may see flashing if the data is very slow. If you would like a blinking LED, LED_2_SEL must be set to Bh.

    Thanks,

    David

  • Hello David, 

    I know that we should set LED_2_SEL to Bh for blinking, but If we set LED_2_SEL to Bh, we can't satisfy two conditions at the same time "Link down :LED_2 turn off" and "Link up + No TX/RX : LED_2 turn off"

    The customer have to find the way to satisfy below condition. Do you mean Is there no way to meet the following conditions with our DP83869HM? 

    Link down :LED_2 turn off

    Link up + No TX/RX : LED_2 turn off

    Link up + TX/RX activity : LED_2 blink

    As mentioned first article, The customer are using DP83869HM to replace comptitor(Broadcom, BCM5482S) so they want to same LED configuration with competitor to be compatible with existing products. So We are looking for ways to make it work the most like our competitors.

    Please review below customer request again and let me know your opinion. 

    1. What is the LED turn-on time when there is one TX/RX signal under (0x18, LED_2_SEL = 1h) condition? 

    2. If we can reduce turn on time when there is a TX/RX signal, I think I can make it work like a competitor. Can this time be set to less than 50 ms?

    Thank you. 

  • Hi Nam,

    There is no way to satisfy all 3 conditions unfortunately. You will have to select option 1h or Bh. 

    1. Under (0x18, LED_2_SEL = 1h) condition, light is constant when there is TX/RX activity. There is no turn-on time.

    2. Turn on time is only applicable under (0x18, LED_2_SEL = Bh) condition. In this case, 50ms is the lowest option for turn on time as shown in register 0x1A.

    Thanks,

    David