Micrel KSZ8091RNA-EVAL, Руководство пользователя

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KSZ8091RNA / KSZ8091RND 10Base-T/100Base-TX Evaluation Board User’s Guide
Micrel, Inc. August 17, 2012
Rev. 1.0
10/11
5V Source JP1 JP4 JP5
RMII connector J4 Close pins 1-2 Close pins 1-2 Close pins 2-3
USB connector CN1 Close pins 2-3 Close pins 2-3 Close pins 1-2
Table 4. 5V Power Source Selection
The 5V is regulated to generate 3.3V for the KSZ8091RNA / KSZ8091RND, the USB interface
chip and the LED. A second voltage regulator optionally supplies reduced I/O voltage for the
KSZ8091RNA / KSZ8091RND.
The I/O voltage level of the KSZ8091RNA / KSZ8091RND can be set to one of three different
levels. The jumper settings for these options are shown in Table 5.
KSZ8091
VDDIO Voltage
JP2 JP3
3.3V Close 1-2 or 2-3 Close pins 2-3
2.5V Close pins 2-3 Close pins 1-2
1.8V Close pins 1-2 Close pins 1-2
Table 5. VDDIO Voltage Selection
4.4 RMII Loopback Jumpers
The KSZ8091RNA-EVAL / KSZ8091RND-EVAL have a set of jumpers that may be used to
loopback the RMII interface. To loopback, all three jumpers must be installed. The individual
jumpers are defined in Table 6.
Jumper RMII Signals Normal Operation RMII Loopback Mode
J1 CRS_DV / TXEN Open Close
J2 RXD1 / TXD1
Open Close
J3 RXD0 / TXD0
Open Close
Table 6. KSZ8091RNA-EVAL / KSZ8091RND-EVAL Loopback Jumper Definition