xmos microcontroller start kit

[raman00084]

i bought a xmos start kit from element 14 in this board there is one 5v pin and 6 ground pins all the ground pins are inter connected internally, if i connect a +5v and ground to any one of the ground pins my board works.
my doubt is why 6 ground given ?

one of my friend said you must connect at-least 3 to 4 grounds from the power supply to eliminate spike in ground i cant understand what is this since all the 6 grounds are inter connected internally why i must connect the same ground to 3 or 4 pins what is the use how it will avoid ground voltage fluctuation.

kindly help


regards
kalyan

 

[tggzzz]

There are two fundamental reasons.

Firstly connectors have a limited current carrying capacity; try to put too much current through one and there will be a voltage drop across the connector and it will get hot.

Secondly, and more likely in this case, "ground bounce", and "signal integrity". Google those search terms and all will, eventually, become clear.

 

[betwixt]

There are several XMOS devices at Element 14, which do you have?

Probably for one of these two reasons:

1. internally, one alone may not be able to carry all the current demand of the product.
2. using parallel grounds reduces the impedance between internal parts and the external grounds. This may help to reduce noise and unwanted signal transitions.

Brian.