EVB-LAN9353 Datasheet, PDF (17/43 Pages) Microchip Technology – EVB-LAN9353 Evaluation Board User’s Guide

EVB-LAN9353
EVALUATION BOARD
USER’S GUIDE
Chapter 3. Board Configuration
3.1 STRAP OPTIONS
The following tables describe the default settings and jumper descriptions for the
EVB-LAN9353. These defaults are the recommended configurations for evaluation of
the LAN9353. These settings may be changed as needed, however, any deviation from
the defaults settings should be approached with care and knowledge of the schematics
and datasheet. An incorrect jumper setting may disable the board.
3.1.1 Jumpers J4:J15
Jumpers J4 through J15 set various functions of the LAN9353. They can also be used
as GPIOs, LED drivers. When used as LED drivers, as they are on the EVB-LAN9353,
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” Figure 3-1 illustrates the schematics connections with the
D3 circuit as a pull-up, and the D4 circuit as a pull-down. To illuminate D3, the LAN9353
will drive the cathode of the D3 low. To illuminate D4, the LAN9353 will drive the cath-
ode of the D4 high.
The J4 - J15 jumpers must be configured in pairs to identical settings in order to realize
the D3 circuit or the D4 circuit. The pairings are as follows:
- J4 & J7
- J6 & J9
- J5 & J8
- J11 & J14
- J10 & J13
- J12 & J15
The following subsections detail the jumper pair settings, their associated strap set-
tings, and the functional effects of setting the straps. All strap values are read during
power-up and on the rising edge of nRST signal. Once the strap value is set, the
LAN9353 will drive the LED’s high or low for illumination according the strap value. For
other designs which may use these pins as GPIOs refer to LAN9353 datasheet for
additional information. In those cases, internal default straps must be changed by an
I2C or SMI master or through EEPROM fields.
 2015 Microchip Technology Inc.
DS50002393A-page 17