WIZnet Developer Forum

Speed Led Behavior

HI guys,

We are porting a board from W5100 to W5500 chip. The new board using W5500 has the following behavior with respect the to speed led:
When the board is powered the led is ON (speed led = low) with no cable attached to RJ45. When we reset the W5500 the led became OFF. When the reset is removed the led turns ON again before any command. The W5100 turns the speed led ON only when we connect the cable and the network speed is 100 MBit.
Any point we missed ?
Could you give us some directions?


Hi, Helio.

when I checked W5100 Schemetic, it supports the speed led.
But W5500 has differences, when I checked W5500 Schemetic, W5500 supports ACRLED, LINKLED, not SPDLED.
I guess that is why you are in confuse.
You can find it with wizwiki.net/wiki/doku.php?id=pro … fschematic .

Thank you,

Hi Lawrence,

Thanks for the feeback. So I´m still confuse. Please check the shematics you send me. What´s the pin 24 function. Is it not the same in W5100 ?

Hi, there

WIZwiki-W7500 is not perfectly the same with W5500.
It has some differences, reg names, porting,…
You can check schemetic with wizwiki.net/wiki/lib/exe/fetch.p … 150401.pdf.
And also there are all documents about W7500 (wizwiki.net/wiki/doku.php?id=pro … 7500:start).

I hope it will help you.

Thank you.

Hi Lawrence,

I found the point we were confused.

Using W5100 the led pin stays in highlevel (led is OFF on our board) when there is no network connected to ethernet interface.

Otherwise, using W5500 the led pin stays in low level (led is ON on our board) when there is no network connected to ethernet interface.

The chips have diferent behavior in this subject.

Thanks again

Hi! Helio,

Please note that the W5500’s PHY is different from W5100’s PHY.
So, the SPDLED signal may operates differently.
Please let us know If the SPDLED indication can be a problem.
For example the LED signal is directly used as some control signal for other systems, etc.

Thank you,

Hi Kevin,

In our project the speed led is used only on yelow led of the RJ45 connector. As today a very few networks use 10 Mbits speed, our costumer see this led the checked if network is connected. Using W5500 this led stays ON regardless the network cable is connected or not. This is not a big problem. We need to change the device manual and post a FAQ with this new behavior.

Anyway, thanks for the interest,


Copyright © 2017 WIZnet Co., Ltd. All Rights Reserved.