LAN9303M Evaluation Board User Manual
Revision 1.0 (05-28-09)
USER MANUAL
SMSC LAN9303M
4
2.1
Jumpers
The following tables describe the default settings and jumper descriptions for the EVB9303M. These
defaults are the recommended configurations for evaluation of the LAN9303M. These settings may be
changed as needed, however, any deviation from the default settings should be approached with care
and knowledge of the schematics and datasheet. An incorrect jumper setting may disable the board.
Note:
A dashed line in the
Settings
column indicates the board’s default jumper setting.
2.1.1
JP1 - JP6
2.1.2
JP7 - JP18
Jumpers JP7 through JP18 set various functions of the LAN9303M. They can also be used as GPIOs,
LED drivers, or interrupts. When used as LED drivers, as they are on the EVB9303M, they are
connected a specific way to set the strap value to a “1”, and another way to set the strap value to a
“0”.
illustrates the schematic connections with the LED1 circuit as a pull-up, and the LED2
circuit as a pull-down. To illuminate LED1, the LAN9303M will drive the cathode of the LED1 low. To
illuminated LED2, the LAN9303M will drive the anode of the LED2 high.
The JP7 - JP18 jumpers must be configured in pairs to identical settings in order to realize the LED1
circuit or the LED2 circuit. The pairings are as follows:
JP7 & JP13
JP8 & JP14
JP9 & JP15
JP10 & JP16
Table 2.1 Jumpers JP1 - JP6
JUMPER
DESCRIPTION
SETTINGS
JP1
C5V DC power
supply
1---2
IN:
C5V brick output to power
plane
OUT:
Disc5V brick power
JP2
Power switch enable jumper
1---2
Enable power switch
2 3
Disable power switch, force power ON
always
JP3
C3.3V jumper
1---2
IN:
C3.3V regulator output to
+3.3V power plane
OUT:
Disc3.3V regulator
JP4
MDIO pull-up/down jumper
1---2
Connect MDIO to 1.5K pull-up to +3.3V
2 3
Connect MDIO to 2.5K pull-down to GND
JP5
MDC pull-down jumper
1---2
IN:
Connect MDC to 10K pull-down
OUT:
Disconnect MDC from 10K pull-
down
JP6
I
2
C connect jumper
1 2
Pins 1 and 2 are +3.3V
3---4
Connect I
2
C EEPROM to SDA
5---6
Connect I
2
C EEPROM to SCL
7---8
Pins 7 and 8 are GND