adder in Qsys

[Altera_Forum]

Hello All, 

 I am very new to this Qsys environment. I developed a adder circuit and would like to develop it as a component in the Qsys environment. I created a new component, entered my verilog adder file, synthesized it without errors. I am stuck with the "Signals" and "Interface" part. My adder has 3 inputs, a,b,cin with sum and carry without any clock or reset. I would like to know how I can create a "Signal/Interface" for this. What interface I should use? I tried with "new_avalon_st_source for "sum/cout", "new_avalon_st_sink" for "a/b/cin", but getting errors. Can someone help me?  Thx, RN

[Altera_Forum]

Where is the component supposed to be connected? 

If the adder i/o data serves a component with an Avalon ST interface, you indeed use avalon ST source/sink. On the other hand, if you want to access it from Nios, you usually create a custom instruction or a MM slave interface. In any case, the interface behaviour is defined by verilog code: you can't simply assign signals in Qsys; if that interface is actually not implemented in the design you'll get errors.

[Altera_Forum]

Hello, 

 Thanks a lot for the information. Is there some document or examples that shows how to develop new components from verilog files and integrate in NIOS II. I have small designs like ripple carry adder, decoders, counters and other circuit written in verilog and I want to connect to NIOSII. I appreciate your help.  Thx, RN

[Altera_Forum]

There's indeed a lot of documentation on this subject. Browse the Altera website and the forum. 

You may start with the Qsys manual, in particular this section: http://www.altera.com/literature/hb/qts/qsys_components.pdf Anyway, if you need to integrate in Nios the small specific functions you pointed out, I'd implement as custom instructions.