SNLA411 October 2022 DP83TC812R-Q1 , DP83TC812S-Q1 , DP83TC813R-Q1 , DP83TC813S-Q1
Wake Forwarding feature in DP83TC812/3 can be leveraged for waking up the whole ethernet network. This section shows a simple ethernet network and timing of the wake-up of all the ethernet PHYs in the network.
When PHY1 wakes-up locally, it powers up and immediately transmits WUP. PHY21 wakes-up on reception of the WUP and immediately transmits >40μs pulse on the WAKE pin. Since the WAKE of PHY21, PHY22 are connected together, PHY22 wakes up after the reception of the >40μs pulse. PHY22 now wakes-up and then transmits WUP which wakes up PHY3.
The following image and table show the wake timing of this network.
The timing numbers are derived based on assumption that power supplies are enabled immediately after INH is driven high and the total supply ramp time is 5 ms. All the timing numbers in the table are tabulated from start of WAKE on PHY1.
Parameter | Event | Units | Min | Typ | Max |
---|---|---|---|---|---|
T6.1 | WUP on MDI line(1,2) | ms | 17.04 | ||
T6.2 | INH high of PHY21 | ms | 17.74 | ||
T6.3 | WAKE pulse output from PHY21 | ms | 18.44 | ||
T6.4 | INH high of PHY22 | ms | 18.48 | ||
T6.5 | WUP on MDI line (2,3) | ms | 35.48 | ||
T6.6 | INH high of PHY3 | ms | 36.18 |