DP83849CVS/NOPB National Semiconductor, DP83849CVS/NOPB Datasheet - Page 20

• Manufacturer Part Number: DP83849CVS/NOPB
• Description: IC TXRX ETHERNET PHY DUAL 80TQFP
• Manufacturer: National Semiconductor
• Type: Transceiverr

Specifications of DP83849CVS/NOPB

• Number Of Drivers/receivers: 2/2
• Protocol: Ethernet
• Voltage - Supply: 3 V ~ 3.6 V
• Mounting Type: Surface Mount
• Package / Case: 80-TQFP, 80-VQFP
• Data Rate: 100Mbps
• Supply Voltage Range: 3V To 3.6V
• Logic Case Style: TQFP
• No. Of Pins: 80
• Operating Temperature Range: 0°C To +70°C
• Msl: MSL 3 - 168 Hours
• Filter Terminals: SMD
• Rohs Compliant: Yes
• Data Rate Max: 10Mbps
• For Use With: DP83849CVS-EVK - BOARD EVALUATION DP83849CVS
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: *DP83849CVS; *DP83849CVS/NOPB; DP83849CVS

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MDIO bus in a system must have a unique physical
address.
The DP83849I supports PHY Address strapping of Port A
to even values 0 (<0000_0>) through 30 (<1111_0>). Port
B is strapped to odd values 1 (<0000_1>) through 31
(<1111_1>). Note that Port B address is always 1 greater
than Port A address.
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 6.0.
Refer to Figure 2 for an example of a PHYAD connection to
external components. In this example, the PHYAD strap-
ping results in address 00010 (02h) for Port A and address
00011 (03h) for Port B.
PHYAD4= 0
Figure 2. PHYAD Strapping Example
PHYAD3 = 0
PHYAD2 = 0
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2.3.1 MII Isolate Mode
The DP83849I can be put into MII Isolate mode by writing
to bit 10 of the BMCR register.
When in the MII isolate mode, the DP83849I does not
respond to packet data present at TXD[3:0], TX_EN inputs
and presents a high impedance on the TX_CLK, RX_CLK,
RX_DV, RX_ER, RXD[3:0], COL, and CRS outputs. When
in Isolate mode, the DP83849I will continue to respond to
all management transactions.
While in Isolate mode, the PMD output pair will not transmit
packet data but will continue to source 100BASE-TX
scrambled idles or 10BASE-T normal link pulses.
The DP83849I can Auto-Negotiate or parallel detect to a
specific technology depending on the receive signal at the
PMD input pair. A valid link can be established for the
receiver even when the DP83849I is in Isolate mode.
PHYAD1 = 1
VCC