06-04-2011 01:57 AM
A very very naive question:
How does one connect a partial bus to a partial bus through bus taps in an ISE schematics, whithout introducing name conflicts?
two input ports in1(1:0) and in2(1:0) have to be connected to an output port out(3:0).
How does one define whether in1(1:0) correspond to out(3:2) or out(1:0)?
When attempting to define it as out(3:2) by double clicking the top tap and renaming it, the whole output bus and IO Marker are renamed out(3:2), which is false:
If I rename the net going from in1(1:0) to the top tap as out(3:2), the IO port in1 is also renamed, which is correct but make the schematics unclear.
What is the solution?
Thanks for your help.
06-04-2011 05:14 AM
A bus can only have one name. You can use buffers to transfer signals from one bus to another.
A buffer does not necessarily add logic to the design, but clarifies the connectivity. In your
case you want to make three buses named in1[1:0], in2[1:0] and out[3:0] and you would
need a 2-wide bus buffer from in1[1:0] to out[1:0] (you can use bus taps between this
buffer and the out bus), and another 2-wide bus buffer from in2[1:0] to out[3:2].