Hi,
I’m planning to add some circuitry to my custom baseboard for the UbiSwitch module, in order to get some “logical” colors for the LEDs indicatin speed/activity of the 8 PHYs (I want 1Gpbs=green, and 100Mbps=orange).
I would like to check 2 elements in order to optimize my circuit :
are the LED outputs push-pull, or open souce / open drain? (I’m particularly interested in the Cx outputs, as I’m feeding them into logic gates, so if it’s not push-pull, I will need to add pull down resistors.
if I understand correctly, the LEDs are time multiplexed, ie they are not all turned on at the same time. If so, I have 2 questions :
2a) Is there a maximal number of LEDs that can be on at the same time (I’m mainly interested of how many LEDs attached on one of the Cx can be turned on at the same time)
2b) what proportion of time is each LED turned on (in order to adjust the resistor to get the same average intensity as the other LEDs on my PCB that are turned on with 100% duty cycle
are the LED outputs push-pull, or open souce / open drain? (I’m particularly interested in the Cx outputs, as I’m feeding them into logic gates, so if it’s not push-pull, I will need to add pull down resistors.
They are push/pull, with internal pullups.
if I understand correctly, the LEDs are time multiplexed, ie they are not all turned on at the same time. If so, I have 2 questions :
2a) Is there a maximal number of LEDs that can be on at the same time (I’m mainly interested of how many LEDs attached on one of the Cx can be turned on at the same time)
2b) what proportion of time is each LED turned on (in order to adjust the resistor to get the same average intensity as the other LEDs on my PCB that are turned on with 100% duty cycle
Unfortunately, I can’t answer this. The way in which the LEDs are specifically driven (duty cycles, timing) is not specified in the datasheet of the main chip, so we don’t know.
I don’t fully understand what you’re trying to achieve. The UbiSwitch baseboard uses the signals to work in a dual-colour mode, where red = 10/100M and Orange = 1000Mbps. As per the UbiSwitch BaseBoard datasheet… Why not just stick with that?
being coherent with the other switch I use to split one of the 1Gbps port into several 100Mbps ports (which uses green=1Gbps, orange=100Mbps (and red = 10Mbps)
to keep the “usual” meaning of the colors : green = everything OK, orange = warning, red= error
And it’s very simple to achieve : just feed C0 into the green LED, and C0 and not C1 into the red LED (same for C2 and C3). Provided the max current is not exceeded, it can be done with a single quad nor IC
being coherent with the other switch I use to split one of the 1Gbps port into several 100Mbps ports (which uses green=1Gbps, orange=100Mbps (and red = 10Mbps)
Can you clarify what you mean by that? How do you plan to split a 1Gbps into several 100Mbps?
to keep the “usual” meaning of the colors : green = everything OK, orange = warning, red= error
I don’t understand this reasoning. A 10/100M connection being may not mean a warning or error. It could be that the device you’ve connected is only capable of 10/100BASE-T, in which case it wouldn’t be an error, rather it would be expected behaviour. The only case where I can think this intuition makes sense is if, say, you are only ever going to be connecting 1000BASE-T devices, and the cable you used is poor quality, in which case the link auto-negotiates down to 10/100BASE-T. I’d be a little careful applying human-level concepts of red/orange/green (error/warning/working) to tri-colour signalling for ethernet LEDs.
And it’s very simple to achieve : just feed C0 into the green LED, and C0 and not C1 into the red LED (same for C2 and C3). Provided the max current is not exceeded, it can be done with a single quad nor IC
Can you provide your circuitry, I’m not sure I follow what you’re trying to achieve. The main issue you have is that, on UbiSwitch:
By splitting, I mean using a smaller switch IC to have 1Gbps upstream comming from the botblox, and several 100Mbps downstream, in order to increase the number of ethernet connection, while guaranteeing there is no possible bottleneck (and plenty of our loads only support 100Mbps anyway)
And yes, a 100Mbps is not an error. At least not when the connected device isn’t capable of more (but then it will probably be connected on a 100Mbps port on the secondary switch and not on the botblox : we keep the precious 1Gbps connections for where they are useful)
yes, that’s it. We need more than 8 ethernet connexions, but not all of them need to be 1GBASE-T, so we use an extra switch (less powerfull than the botblox, but enough to get extra 100BASE-TX connections)
