KS8721BL/SL
Pin Number
19
20
21
Pin Name
TXD2
TXD3
COL/RMII
Type
(1)
Ipd
Ipd
Ipd/O
Pin Function
MII Transmit Data Input.
MII Transmit Data Input.
Micrel
MII Collision Detect Output.
During reset, the pull-up/pull-down value is latched as RMII select. See “Strapping
Options” section for details.
MII Carrier Sense Output.
During reset, the pull-up/pull-down value is latched as RMII back-to-back mode
when RMII mode is selected. See “Strapping Options” section for details.
Ground.
Digital IO 2.5/3.3V tolerant power supply. 3.3V power input of voltage regulator.
See “Circuit Design Ref. for Power Supply” section for details.
Management Interface (MII) Interrupt Out. Interrupt level set by
Register 1f, bit 9.
During reset, latched as PHYAD[0]. See “Strapping Options” section for details.
Link/Activity LED Output. The external pull-down enable test mode and only used
for the factory test. Active low.
Link/Act
No Link
Link
Act
Pin State
H
L
—
LED Definition
“Off”
“On”
“Toggle”
PHYAD0
22
CRS/
RMII_BTB
GND
VDDIO
INT#/
PHYAD0
LED0/TEST
Ipd/O
23
24
25
GND
P
Ipu/O
26
Ipu/O
27
LED1/
SPD100/
nFEF
Ipu/O
Speed LED Output. Latched as SPEED (Register 0, bit 13) during power-up/
reset. See “Strapping Options” section for details. Active low.
Speed
10BT
100BT
Pin State
H
L
LED Definition
“Off”
“On”
28
LED2/
Ipu/O
Full-duplex LED Output. Latched as DUPLEX (register 0h, bit 8) during power-up/
reset. See “Strapping DUPLEX Options” section for details. Active low.
Duplex
Half
Full
Pin State
H
L
LED Definition
“Off”
“On”
29
LED3/
NWAYEN
Ipu/O
Collision LED Output. Latched as ANEG_EN (register 0h, bit 12) during power-up/
reset. See “Strapping Options” section for details.
Collison
No Collision
Collision
Pin State
H
L
LED Definition
“Off”
“On”
30
Notes:
1. P = Power supply.
GND = Ground.
I = Input.
I/O = Bidirectional.
PD#
Ipu
Power Down. 1 = Normal operation, 0 = Power-down. Active low.
Ipd = Input w/ internal pull-down.
Ipd/O = Input w/ internal pull-down during reset, output pin otherwise.
Ipu = Input w/ internal pull-up.
Ipu/O = Input w/ internal pull-up during reset, output pin otherwise.
O = Output.
May 2004
7
M9999-051704
MICREL [ MICREL SEMICONDUCTOR ]
