Carry-Select on Stratix

Hi,

I've come up with a design to implement Carry-Select adder on stratix logic block (as shown in the schematic attached). I want to implement it using low-level primitives, but the primitives are somehow confusing; i can't see how carry_sum primitive can be useful for example..

i also tried to use the starix_lcell component but there are two problems:

- the component is again unclear and i'm not sure if it works for "arithmetic" mode

- and maybe more importantly, i guess components like stratix_lcell or any other one from sim_lib are just for having a percise simulation and not implementation of logic

i looked @ the previous forums available but i didn't get a clear answer..i guess there should be some components and a straight forrward way to implement logic in the LEs and LABs as presented in the Stratix handbook..

i've reviewed Stratix cookbook too but it didn't help actually for following reasons:

- it's designed for stratix II and later versions not stratix itself..the structure of LEs and LABs are a little different

- the codes available in the cookbook examples are mostly behavioral description and they don't use primitives..

i'm new with using primitives in Altera, but i'm not new to the topic and i tried different ways..so i need a little more help than just being referred to cookbook or being suggested generally to use carry_sum for example..an example of using LEs and LABs of stratix in arithmetic mode would be great if u can provide me some..

now i'm just testing various behavioral codes to see if i luckily find a way for compiler to realize what i want..

regards,

babak