±15kV ESD Protected MII/RMII 10/100 Ethernet Transceiver with HP Auto-MDIX Support and flexPWR® Technology in a Small Footprint
Datasheet
Chapter 3 Pin Description
This chapter describes the signals on each pin. When a lower case “n” is used at the beginning of the
signal name, it indicates that the signal is active low. For example, nRST indicates that the reset signal
is active low.
3.1
I/O Signals
The following buffer types are shown in the TYPE column of the tables in this chapter.
I
Input. Digital LVCMOS levels.
IPD
O
Input with internal pull-down. Digital LVCMOS levels.
Output. Digital LVCMOS levels.
OPD
I/O
Output with internal pull-down. Digital LVCMOS levels.
Input or Output . Digital LVCMOS levels.
IOPD
IOPU
Input or Output with internal pull-down. Digital LVCMOS levels.
Input or Output with internal pull-up. Digital LVCMOS levels.
Note: The digital signals are not 5V tolerant.They are variable voltage from +1.6V to +3.6V.
AI
Input. Analog levels..
Output. Analog levels.
AO
Table 3.1 MII Signals
SIGNAL NAME
TYPE
DESCRIPTION
TXD0
I
Transmit Data 0: Bit 0 of the 4 data bits that are accepted by
the PHY for transmission.
TXD1
TXD2
I
I
Transmit Data 1: Bit 1 of the 4 data bits that are accepted by
the PHY for transmission.
Transmit Data 2: Bit 2 of the 4 data bits that are accepted by
the PHY for transmission
Note:
This signal should be grounded in RMII Mode.
TXD3
I
Transmit Data 3: Bit 3 of the 4 data bits that are accepted by
the PHY for transmission.
Note:
This signal should be grounded in RMII Mode
nINT/
TX_ER/
TXD4
IOPU
MII Transmit Error: When driven high, the 4B/5B encode
process substitutes the Transmit Error code-group (/H/) for the
encoded data word. This input is ignored in 10Base-T operation.
MII Transmit Data 4: In Symbol Interface (5B Decoding) mode,
this signal becomes the MII Transmit Data 4 line, the MSB of the
5-bit symbol code-group.
Notes:
This signal is not used in RMII Mode.
This signal is mux’d with nINT
See Section 4.10, "nINT/TX_ER/TXD4 Strapping," on page 32
for additional information on configuration/strapping options.
TX_EN
IPD
Transmit Enable: Indicates that valid data is presented on the
TXD[3:0] signals, for transmission. In RMII Mode, only TXD[1:0]
have valid data.
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