Help needed to design recursive digital circuit

PiyushG schrieb:

Hi Piyush, first of all...why do you want to manipulate your *.vhf file? if you are designing a schematic, you can use your schematic editor, which creates a *.sch file. The *.vhf file is generated from the schematic file, and might be overwritten by the IDE.

Now, if you already have designed your barrelshiftersave it, go back to the ide and generate a symbol out of the schematic (Look under design entry tools). Open a new schematic and place the barrel schifter symbol there. Well, now you are free to connect the outputs to the inputs with a bus or wires, if it makes any sense. Maybe you should think about a multiplexer, to feed in your initial data and then switch to the feedback, and a register would be nice to prevent a combinatorial loop, if your barrel shifter doesn't already have it.

At last please tell me what you mean by "recursive"? Recursion is not equal to feeding data back into a function (block), which can be seen as looping. In software it only works, because you have lots of RAM and your function can allocate new workspaces (for variables etc.) until the problem deepth is reached and the results can be accumulated somehow on the way back to the first calling function, or...until your ram limit is reached. (Without thinking about the stack) This is a virtual behavior. Workspaces are created as needed. How should that happen in hardware? Function blocks do not virtually pop out of nowhere. It is surely possible to create a hardware that behaves to a certain limit like a recursive algorithm, but then, only a very limited number of algorithms need real recursion. In software mostly everything can be expressed different, though not even as elegant.

have a nice synthesis Eilert