Forum Discussion
Full Rate Mode in DDR2 HP Controller
Hello, I'm new to the High-Performance DDR2 Controller and have a question about the documentation that I hope some can clear up. I want to run my controller in Full Rate Native Interface Mode but I don't see any timing diagrams for that mode. Can anyone explain this, or maybe there is not such a mode?
thanks, joe6 Replies
- Altera_Forum
Honored Contributor
All timing diagrams in HP controller manual are for native mode, full rate, as said at page 4-11.
- Altera_Forum
Honored Contributor
Hello, thanks for responding to my post. I looked at page 4-11 and I only see timing diagrams for
Full Rate Write Avalon Interface, Half Rate Write, Native Full Rate Read Avalon Interface Half Rate Read Avalon Interface. But I don't see a Full Rate Native Interface Mode, which timing diagram should I follow? Sorry for being so stupid here and I appreciate your patients. Thanks, joe - Altera_Forum
Honored Contributor
I refer to ddr & ddr2 sdram high-performance controller v7.2 user guide
--- Quote Start --- These interface requests are for the native interface. ... All figures show full rate controllers. --- Quote End --- - Altera_Forum
Honored Contributor
Hello, now I see the disconnect. I'm using DDR & DDR2 SDRAM High-Performance Controller v8.0 User Guide documentation which is different than 7.2. Do you think there is a difference between 7.2 and 8.0? Looking at the timing diagrams briefly there appears some difference. Could you you at the 8.0 doc and comment on what they have when you have some free time.
Thanks for your help, joe - Altera_Forum
Honored Contributor
Looking closer at 7.2 I see that the local_addr is broken down into other signals this is not done in 8.0, do you know where I can find where it breaks that down. I've looked through the verilog code but I can't find that information.
thanks, joe - Altera_Forum
Honored Contributor
I downloaded Quartus V8.0, but didn't yet install it. I don't expect, that the basic decoding scheme of local addresses has been changed with V8.0 HP controller, cause the mapping is almost obvious and doesn't give much room for alternatives to my opinion. But I may be wrong. I also wasn't aware of big differences in local bus interface timing between half and full rate, except for the latency when measured in clock cycles.
However, I'll take a look at the V8.0 HP controller.