[chbot] Quartus II licensing of NIOS II

[Charles Manning]

On Sunday 24 July 2011 12:44:35 Mark Atherton wrote:
> Charles,
>
> Did you spot the time-limiting caveat associated with the Quartus II
> download with the NIOS II system generator ?

There are three flavours of NIOS2.

/e: No licensing restrictions. Limited. No cache or MMU. Can't run Linux 
because there is no MMU. Can run ucLinux and other RTOSs.

/s and /f: More capable with caches and MMU. Licencing restrictions apply.

The restrictions on /s and /f are that the processor can be run in one of two 
modes:

* Tethered: Must be connected via USB cable to development software running on 
the host. Will run forever in this mode.
* Untethered: Need not be tethered, but will only run for a fixed time (??not 
sure how long??) and then the CPU halts.


Thus, the nios does have some limitations but can still do what we need for 
learning, particularly in the earlier "training wheels" stage.

As alternatives there are many non-restricted cores available for download. 
Many of these include Linux support.

If people want to run Linux on the board, I would suggest using nios to get 
their head around tools, then switch to one of the other cores to get away 
from restrictions.

-- Charles