Data Sheet

Ethernet Controller I210 —Design Considerations
830
Figure 12-19.NC-SI Connection Requirements - Hardware Arbitration
12.6.1.3 Resets
It is important to ensure that the resets for the MC and I210 are generated within a specific time
interval. The important requirement here is ensuring that the NC-SI link is established within two
seconds of the MC receiving the power good signal from the platform. Both I210 and the external MC
need to receive power good signals from the platform within one second of each other.
This causes an internal power on reset within I210 and then initialization as well as a triggering and
initialization sequence for the MC. Once these power good signals are received by both I210 and the
external MC, the NC-SI interface can be initialized. The NC-SI specification calls out a requirement of
link establishment within two seconds. The MC should poll this interface and establish a link for two
seconds to ensure specification compliance.
12.6.1.4 Layout Requirements
12.6.1.4.1 Board Impedance
The NC-SI signaling interface is a single-ended signaling environment with a target board and trace
impedance of 50  plus 20% and minus 10% is recommended. This target impedance ensures optimal
signal integrity and signal quality.
12.6.1.4.2 Trace Length Restrictions
Intel recommends a trace length maximum value from a board placement and routing topology
perspective of eight inches for direct connect applications (Figure 12-20). This ensures that signal
integrity and quality is preserved from a design perspective and that compliance is met for the NC-SI
electrical requirements.