Datasheet

 2013-2015 Microchip Technology Inc. DS00001987A-page 7
LAN8740A/LAN8740Ai
TABLE 2-1: MII/RMII SIGNALS
Num Pins Name Symbol Buffer Type Description
1 Transmit
Data 0
TXD0 VIS The MAC transmits data to the transceiver using
this signal in all modes.
1 Transmit
Data 1
TXD1 VIS The MAC transmits data to the transceiver using
this signal in all modes.
1 Transmit
Data 2
(MII Mode)
TXD2 VIS The MAC transmits data to the transceiver using
this signal in MII mode.
Note: This signal must be grounded in RMII
mode.
1 Transmit
Data 3
(MII Mode)
TXD3 VIS The MAC transmits data to the transceiver using
this signal in MII mode.
Note: This signal must be grounded in RMII
mode.
1 Interrupt Out-
put
nINT VOD8
(PU)
Active low interrupt output. Place an external resis-
tor pull-up to VDDIO.
Note: The nINT signal can be optionally con-
figured to output on the LED1 or LED2
pins. Refer to Section 3.6, "Interrupt
Management" for additional details on
device interrupts.
Note: Refer to Section 3.8.1.6, "nINTSEL and
LED2 Polarity Selection" for details on
how the nINTSEL
configuration strap is
used to determine the function of this
pin.
Transmit Error
(MII Mode)
TXER VIS When driven high, the 4B/5B encode process sub-
stitutes the Transmit Error code-group (/H/) for the
encoded data word. This input is ignored in the
10BASE-T mode of operation. This signal is also
used in EEE mode as TXER when TXEN = 1, and
as LPI when TXEN = 0.
Note: This signal is not used in RMII mode.
Transmit
Data 4
(MII Mode)
TXD4 VIS
(PU)
In Symbol Interface (5B decoding) mode, this sig-
nal becomes the MII Transmit Data 4 line (the MSB
of the 5-bit symbol code-group).
Note: This signal is not used in RMII mode.
1 Transmit
Enable
TXEN VIS
(PD)
Indicates that valid transmission data is present on
TXD[3:0]. In RMII mode, only TXD[1:0] provide
valid data.
1 Transmit Clock
(MII Mode)
TXCLK VO8 Used to latch data from the MAC into the trans-
ceiver.
• MII (100BASE-TX): 25 MHz
• MII (10BASE-T): 2.5 MHz
Note: This signal is not used in RMII mode.