SMSC LAN8720, LAN8720i Chapter 6 AC Electrical Characteristics, 6.1Serial Management Interface (SMI) Timing, MDC, MDIO, MDIO, DATASHEET, MIN, TYP, MAX, UNITS, NOTES, PARAMETER

Small Footprint RMII 10/100 Ethernet Transceiver with HP Auto-MDIX Support

Datasheet

Chapter 6 AC Electrical Characteristics

The timing diagrams and limits in this section define the requirements placed on the external signals of the Phy.

6.1Serial Management Interface (SMI) Timing

The Serial Management Interface is used for status and control as described in Section 4.14.

						T1.1
Clock -
MDC
				T1.2
Data Out -						Valid Data
MDIO						(Read from PHY)
	T1.3				T1.4
Data In -			Valid Data
MDIO		(Write to PHY)

Figure 6.1 SMI Timing DiagramTable 6.1 SMI Timing Values

PARAMETER	DESCRIPTION	MIN	TYP	MAX	UNITS	NOTES
T1.1	MDC minimum cycle time	400			ns
T1.2	MDC to MDIO (Read from PHY)	0		30	ns
	delay
T1.3	MDIO (Write to PHY) to MDC setup	10			ns
T1.4	MDIO (Write to PHY) to MDC hold	10			ns

SMSC LAN8720/LAN8720i	55	Revision 1.0 (05-28-09)
	DATASHEET