
LAN9303 Evaluation Board User Manual
SMSC LAN9303
USER MANUAL
Revision 1.0 (05-28-09)
5
JP11 & JP17
JP12 & JP18
The following subsections detail the jumper pair settings, their associated strap settings, and the
functional effects of setting the straps. All strap values are read during power-up and on the rising edge
of the nRST signal. Once the strap value is set, the LAN9303 will drive the LEDs high or low for
illumination according the strap value. For other designs which may use these pins as GPIOs or
interrupts, refer to the LAN9303 datasheet for additional information. In those cases, internal default
straps must be changed by an I
2
C or SMI master or through EEPROM fields.
2.1.2.1
Auto-MDIX / EEPROM Jumpers
Note 2.1
Paired jumpers
MUST
be set identically.
Note 2.2
The EVB9303 uses an 8Kx8 EEPROM. Therefore, this jumper
MUST
be set to 1-2.
Figure 2.2 LED Strap Circuit
Table 2.2 Jumpers - Auto-MDIX / EEPROM
JUMPER PAIR
DESCRIPTION
SETTINGS
JP7, JP13
Port 1 Auto-MDIX
enable/disable (
1---2
Enable Auto-MDIX on Port 1
2 3
Disable Auto-MDIX on Port 1
JP8, JP14
Port 2 Auto-MDIX
enable/disable (
1---2
Enable Auto-MDIX on Port 2
2 3
Disable Auto-MDIX on Port 2
JP9, JP15
EEPROM size jumper
,
1---2
Enable 4Kx8 and larger I
2
C EEPROMs
2 3
Enable 2Kx8 and smaller I
2
C EEPROMs
+3.3V
Strap Pullup
R2
10.0K
1/16W
1%
R1
332
1/10W
1%
LED1
R3
10.0K
1/16W
1%
LED2
R4
332
1/16W
1%
Strap Pulldown