SNLS614A September 2018 – December 2018 DP83869HM
The DP83869HM includes advanced link-down capabilities that support various real-time applications. The link down mechanism is configurable and includes enhanced modes that allow extremely fast reaction times to link drops.
As described in Figure 20, the link loss mechanism is based on a time window search period in which the signal behavior is monitored. The T1 window is set by default to reduce typical link drops to less than 1 ms in 100M and 0.5 ms in 1000M mode.
The DP83869HM supports enhanced modes that shorten the window called Fast Link Down mode. In this mode, the T1 window is shortened significantly, in most cases less than 10 μs. In this period of time, there are several criteria allowed to generate link loss event and drop the link:
The Fast Link Down functionality allows the use of each of these options separately or in any combination. Note that because this mode enables extremely quick reaction time, it is more exposed to temporary bad link quality scenarios.