ZHCSAB9E September 2012 – June 2019 DP83848-EP
PRODUCTION DATA.
The 5 PHY address inputs pins are shared with the RXD[3:0] pins and COL pin are shown below.
Pin No. | PHYAD Function | RXD Function |
---|---|---|
42 | PHYAD0 | COL |
43 | PHYAD1 | RXD_0 |
44 | PHYAD2 | RXD_1 |
45 | PHYAD3 | RXD_2 |
46 | PHYAD4 | RXD_3 |
The DP83848-EP can be set to respond to any of 32 possible PHY addresses via strap pins. The information is latched into the PHYCR register (address 19h, bits [4:0]) at device power-up and hardware reset. The PHY Address pins are shared with the RXD and COL pins. Each DP83848-EP or port sharing an MDIO bus in a system must have a unique physical address.
The DP83848-EP supports PHY Address strapping values 0 (<00000>) through 31 (<11111>). Strapping PHY Address 0 puts the part into Isolate Mode. It should also be noted that selecting PHY Address 0 via an MDIO write to PHYCR will not put the device in Isolate Mode. See Section 5.4.4.1 for more information.
For further detail relating to the latch-in timing requirements of the PHY Address pins, as well as the other hardware configuration pins, refer to the Reset summary in Section 5.4.6.
Because the PHYAD[0] pin has weak internal pullup resistor and PHYAD[4:1] pins have weak internal pulldown resistors, the default setting for the PHY address is 00001 (0x01h).
Refer to Figure 5-4 for an example of a PHYAD connection to external components. In this example, the PHYAD strapping results in address 000101 (0x03h).