KSZ9021GN TR Micrel Inc, KSZ9021GN TR Datasheet - Page 14

• Manufacturer Part Number: KSZ9021GN TR
• Description: Specifications: Number of Drivers/Receivers: 8/8 ; Type: Transceiver ; Voltage - Supply: 3.135 V ~ 3.465 V ; Package / Case: 64-VFQFN Exposed Pad ; Packaging: Tape & Reel (TR) ; Protocol: Gigabit Ethernet ; Lead Free Status: Lead Free ; RoHS Stat
• Manufacturer: Micrel Inc

Micrel, Inc.
Strapping Options
Note:
1.
Pin strap-ins are latched during power-up or reset. In some systems, the MAC receive input pins may be driven during
power-up or reset, and consequently cause the PHY strap-in pins on the GMII/MII signals to be latched to the incorrect
configuration. In this case, it is recommended to add external pull-ups/pull-downs on the PHY strap-in pins to ensure
the PHY is configured to the correct pin strap-in mode.
September 2010
Pin Number
I/O = Bi-directional.
48
17
19
39
41
43
44
45
55
CLK125_EN
LED_MODE
Pin Name
PHYAD2
PHYAD1
PHYAD0
MODE3
MODE2
MODE1
MODE0
Type
I/O
I/O
I/O
I/O
I/O
I/O
I/O
I/O
I/O
(1)
Pin Function
The PHY Address, PHYAD[2:0], is latched at power-up / reset and is configurable to
any value from 1 to 7. Each PHY address bit is configured as follows:
PHY Address bits [4:3] are always set to ‘00’.
The MODE[3:0] strap-in pins are latched at power-up / reset and are defined as
follows:
CLK125_EN is latched at power-up / reset and is defined as follows:
Pin 55 (CLK125_NDO) provides the 125MHz reference clock output option for use by
the MAC.
LED_MODE is latched at power-up / reset and is defined as follows:
MODE[3:0]
0000
0001
0010
0011
0100
0101
0110
0111
1000
1001
1010
1011
1100
1101
1110
1111
Pull-up = 1
Pull-down = 0
Pull-up = Enable 125MHz Clock Output
Pull-down = Disable 125MHz Clock Output
Pull-up = Single LED Mode
Pull-down = Tri-color Dual LED Mode
Mode
Reserved – not used
GMII / MII Mode
Reserved – not used
Reserved – not used
NAND Tree Mode
Reserved – not used
Reserved – not used
Chip Power Down Mode
Reserved – not used
Reserved – not used
Reserved – not used
Reserved – not used
Reserved – not used
Reserved – not used
Reserved – not used
Reserved – not used
14
M9999-091010-1.1
KSZ9021GN