Datasheet

10 www.national.com
2.0 Pin Description (Continued)
DP83815
Note: DP83815 supports FM93C46 for the EEPROM device.
Clock Interface
Symbol
LQFP Pin
No(s)
LBGA Pin
No(s) Dir Description
X1 17 D8 I Crystal/Oscillator Input: This pin is the primary clock reference
input for the DP83815 and must be connected to a 25 MHz 0.005%
(50ppm) clock source. The DP83815 device supports either an
external crystal resonator connected across pins X1 and X2, or an
external CMOS-level oscillator source connected to pin X1 only.
X2 18 C7 O Crystal Output: This pin is used in conjunction with the X1 pin to
connect to an external 25 MHz crystal resonator device. This pin
must be left unconnected if an external CMOS oscillator clock source
is utilized. For more information see the definition for pin X1.
LED Interface
Symbol
LQFP Pin
No(s)
LBGA Pin
No(s) Dir Description
LEDACTN/MA0 142 C14 O TX/RX Activity: This pin is an output indicating transmit/receive
activity. This pin is driven low to indicate active transmission or
reception, and can be used to drive a low current LED (<6 mA). The
activity event is stretched to a min duration of approximately 50 ms.
LED100N/MA2 144 C13 O 100 Mb/s Link: This pin is an output indicating the 100 Mb/s Link
status. This pin is driven low to indicate Good Link status for 100
Mb/s operation, and can be used to drive a low current LED (<6 mA).
LED10N/MA1 143 C12 O 10 Mb/s Link: This pin is an output indicating the 10 Mb/s Link
status. This pin is driven low to indicate Good Link status for 10 Mb/s
operation, and can be used to drive a low current LED (<6 mA).
Serial EEPROM Interface
Symbol
LQFP Pin
No(s)
LBGA Pin
No(s) Dir Description
EESEL 128 G14 O EEPROM Chip Select: This signal is used to enable an external
EEPROM device.
EECLK/MA4 2 A12 O EEPROM Clock: During an EEPROM access (EESEL asserted),
this pin is an output used to drive the serial clock to an external
EEPROM device.
EEDI/MA3 1 B12 O EEPROM Data In: During an EEPROM access (EESEL asserted),
this pin is an output used to drive opcode, address, and data to an
external serial EEPROM device.
EEDO/MD4 138 E11 I EEPROM Data Out: During an EEPROM access (EESEL asserted),
this pin is an input used to retrieve EEPROM serial read data.
This pin has an internal weak pull up.
MD1/CFGDISN 133 F13 I/O Configuration Disable: When pulled low at power-on time, disables
load of configuration data from the EEPROM. Use 1 KΩ to ground to
disable configuration load.
Obsolete