Datasheet
2016-2018 Microchip Technology Inc. DS00002202C-page 11
KSZ8081MNX/RNB
14 PHYAD1 Ipd/O
The pull-up/pull-down value is latched as PHYADDR[1] at
the de-assertion of reset.
See the Strap-in Options – KSZ8081RNB section for
details.
15
RXD1/
PHYAD2
Ipd/O
RMII Mode: RMII Receive Data Output[1]
(Note 2-2).
Config Mode: The pull-up/pull-down value is latched as
PHYADDR[2] at the de-assertion of reset.
See the Strap-in Options – KSZ8081RNB section for
details.
16
RXD0/
DUPLEX
Ipu/O
RMII Mode: RMII Receive Data Output[0]
(Note 2-2).
Config Mode: The pull-up/pull-down value is latched as
DUPLEX at the de-assertion of reset.
See the Strap-in Options – KSZ8081RNB section for
details.
17 VDDIO P 3.3V, 2.5V, or 1.8V digital V
DD
.
18
CRS_DV/
CONFIG2
Ipd/O
RMII Mode: RMII Carrier Sense/Receive Data Valid Out-
put.
Config Mode: The pull-up/pull-down value is latched as
CONFIG2 at the de-assertion of reset.
See the Strap-in Options – KSZ8081RNB section for
details.
19
REF_CLK/
B-CAST_OFF
Ipd/O
RMII Mode:
25 MHz Mode: This pin provides the 50 MHz RMII refer-
ence clock output to the MAC. See also XI (Pin 9).
50 MHz mode: This pin is a no connect. See also XI (Pin
9).
Config Mode: The pull-up/pull-down value is latched as B-
CAST_OFF at the de-assertion of reset.
See the Strap-in Options – KSZ8081RNB section for
details.
20
RXER/
ISO
Ipd/O
RMII Mode: RMII Receive Error Output.
Config Mode: The pull-up/pull-down value is latched as
ISOLATE at the de-assertion of reset.
See the Strap-in Options – KSZ8081RNB section for
details.
21
INTRP/
NAND_Tree#
Ipu/Opu
Interrupt Output: Programmable Interrupt Output.
This pin has a weak pull-up, is open-drain, and requires
an external 1.0 k pull-up resistor.
Config Mode: The pull-up/pull-down value is latched as
NAND Tree# at the de-assertion of reset.
See the Strap-in Options – KSZ8081RNB section for
details.
22 NC —
No Connect. This pin is not bonded and can be left
floating.
23 TXEN I RMII Transmit Enable input.
24 TXD0 I RMII Transmit Data Input[0]
(Note 2-3).
25 TXD1 I RMII Transmit Data Input[1]
(Note 2-3).
26 NC —
No Connect. This pin is not bonded and can be left
floating.
27 NC —
No Connect. This pin is not bonded and can be left
floating.
TABLE 2-3: PIN DESCRIPTION — KSZ8081RNB (CONTINUED)
Pin Number Pin Name Type (Note 2-1) Pin Function