Thanks for your respond. After you told me to verify timing and connection, I have been checking my design inside out. I have a stupid question and believe this is the source of the problem if anyone could kindly help me out.
As a beginner, I would like to learn the NIOSII from bottom up. Therefore, I started the QSYS design from scratch and following the same design in the Application Selector tutorial. I am using the Quartus II 12.1 web edition with development kit - NEEK. I believe my source of the problem is the SDRAM PSC A2S56D40CTP-G5 isn't configure correctly. I would think it will work if I take the (DDR2 SDRAM controller with ALTMEMPHY) - memory present from the Applicatin Selector tutorial which I saved it as the PSC A2S56D40CTP-G5.xml file and then load it into my new design present. Nonetheless, I got this error message:
The value (0.0) of the parameter 'mem_trrd_ns' is out of range.
Valid values for this parameter are between 5.5 and 106.0
So, I went in to edit it, and then I got a dialog box error message: The memory type of 'PSC A2S56D40CTP-G5.xml' is not compatible with this wizard
I was able to take the other memory present (Micron MT47H32M16-3E) and customized it to look alike the tutorial show. However, there were some additional parameters are different.
-Four active window time (tFAW)
-Read to precharge time(tRTP)
-Maximum memory frequency for CAS latency 3.0/4.0/5.0/6.0 while the tutorial parameter only have 2.0/2.5/3.0
By adding 2.0/2.5 into the memory present file, I got this error message
Parameter 'mem_tcl_20_fmax' is an unknown parameter.
Parameter 'mem_tcl_25_fmax' is an unknown parameter.
I believe the DDR2 configuration with the QSYS is incorrect which causing many other issues. How come the Application Selector tutorial didn't get all these error msg? it was build by SOPC builder and converted into QSYS.. Maybe that's why?
I greatly appreciated if you anyone could help me. This problem is getting onto my nerve..haha
-Yeung