Dual DP83640 Ethernet PHY HSMC Daughter Board
Reference Guide
V1.0 - October 2013
13
6 MDIO Management
The PHYs can be configured for several modes of operation through the 2-wire MDIO/MDC
management interface.
Both PHY devices share the same mdio/mdc bus. The PHYs support an MDC clock of up to
25MHz.
The PHYs support a so-called broadcast function when commands are sent to the PHY
address 31, which then will be accepted by both PHYs at the same time.
The PHYs can be individually addressed using the following MDIO addresses.
Table 4: PHY MDIO Addresses
MDIO Address
PHY
1
Port 0 (Left RJ45 Connector, J5)
3
Port 1 (Right RJ45 Connector, J6)
31
Broadcast to both PHYs. Writes a register in both PHYs at the
same time. Should be used for write commands only.
