SMSC UG - EVB-20020

Page 5

Rev. 1/5/00

Jumpers

There are three sets of jumper blocks on the EVB-20020 board. JP1-4 selects the clock speed of the network

controller. JP1 and JP2 MUST BE INSTALLED for proper operation. JP3 and JP4 are for future use and should be

left unconnected. JP9, JP10, and JP11 select the source of data for the network controller’s receiver. JP12 – 17 are

used to choose the media type. Refer to the following table for the correct jumper settings:

MEDIA TYPE

CONNECT JUMPERS

Coax

JP11

Twisted Pair

JP11, JP16, JP17

Direct RS-485

JP9, JP12, JP13

Isolated RS-485

JP10, JP14, JP15

Interrupts

If your software is to be interrupt driven, the priority of the interrupt is selected through JP5-JP8 (IRQ3-6).