Riding the Eagle Cad Data bus (Eagle question)

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Mikebits

Well-Known Member
In using the Eagle data bus tool, I get an ERC error that my data pins are not connected. I have clicked on the Bus properties and named it D0-D7 but this does not work. The data bus draw feature makes for a much cleaner design so what am I not doing to make the dbus work?
Below is a image.

**broken link removed**
 
Hi Mike,

you're using the wrong syntax. Buses should consist of one ore more letters a rectangular bracket and the numbers of data lines including two dots between first and last number, e.g. D0 to D7 should have the netname D[0..7].

Using more signals e.g. D0 to D7, A0 to A14, SCK, SDL, VCC and GROUND the bus name should be "D[0..7],A[0..14],SCK,SDL,VCC,GND".

Don't use the space key when putting in the values and use a comma to separate items.

Always draw nets from the bus to the component pin. When starting a net a popup window will give you the selection e.g. D, A, SCK, SDL, VCC AND GND and one more window, e.g. D0 to D7 when selecting "D".

Take a look at the connector and the bus as attached.

Regards

Boncuk
 

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  • BUS.gif
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Okay, I tried it and still some questions. Do I need to label the net on each device attached to the bus, ie. D0 on U1 and D0 on U2? I tried doing this and I get a netname in use error.

Thanks
 
Hi Mike,

it would be more than wise to label all nets into and out of a bus. Labeling the nets you can catch errors easily. If you inadvertantly use eg. D3 instead of D2 you won't catch that error on the PCB-design.

My version of Eagle (3.55) won't object if I connect the wrong data line to a pin. I haven't tried the newer versions if they check the logic of connections.

Please post a screenshot of the schematic and the error message for further assistance.

Regards

Boncuk
 

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