[En-Nut-Discussion] question about connection of lan91c111

[Harald Kipp]

wjquyi at sina.com schrieb:
> I am new here.There are two questions.
> 1.The group of D0-D7 and the goup of D8-D15 are connected Correspondingly on lan91c111
> in Ethernut 2.0 or 2.1.why?I think that only D0-D7 on lan91c111 should be connected to D0-D7 of ATMEGA128.
>   
Actually the SMSC is driven in 16-bit mode, using nBE0 and nBE1 to 
select the lower and upper byte of the databus.
> 2.May I use two layers board to make Ethernut2.1.
>
>   
The main reason for using a 4-layer board is to have a reliable ground 
plane. 2-layers will probably work, but be prepared to increase the 
overall board size. Otherwise you may not be able to implement good 
ground and supply traces.

Harald