Jumpers, Buttons and LEDs
Leave this jumper open if you want the NB1010 to run at full speed (88.4736MHz). Close the jumper if you want the NB1010 to run at 1/8th the full speed (11.0592MHz). Notice, that the jumper state is only recognized after the power-up or external reset (caused by pressing the reset button). The PLL mode can also be changed programmatically.
MD jumper and mode button
The function of the mode button is described in Setup Button (MD line). On the NB1010 board, MD jumper is connected in parallel with the button.
This jumper selects the serial port of the NB1010 that will be used for serial firmware upgrades. When the jumper is opened, serial port 1 is used (TX0 (#17) and RX0 (#19) lines on the IC1000 interboard cable). Interface boards typically implement serial port 1, thus making serial firmware upgrades possible.
When the US jumper is closed, debug serial port is used.
Pressing this button causes an "external" reset.
Ethernet Status LEDs
Further information on Ethernet status LEDs can be found in Status LEDs.