- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
I really need to free up some LEs so it would really help if my LPM_MULT blocks could be implemented in the embedded multiplier blocks. How do I do that?
I've looked at the documentation and in Table 25 it suggests that setting DEDICATED_MULTIPLIER_CIRCUITRY to YES is the way forward, but where do I do that?Link Copied
- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
Hi Oliver,
If you open the LPM_MULT block in the megawizard there is an implementation option where you can select "use dedicated multiplier circuitry". CoGH- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
Yes, I found that, but all the options are greyed out.
- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
Have you selected Cyclone IV in the megawizard?
Otherwise you can edit the .vhd directly and set the DEDICATED_MULTIPLIER_CIRCUITRY parameter.- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
Yes, I've set the Cyclone IV in the megawizard.
I've looked in the .vhd file and it says -- THIS IS A WIZARD-GENERATED FILE. DO NOT EDIT THIS FILE! This doesn't surprise me, and I guess I can ignore it. When you suggest setting DEDICATED_MULTIPLIER_CIRCUITRY, what's the syntax and where in the file does it belong?- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
It should already be there if it is a valid setting.
I created an LPM_MULT for Cycline IV in Quartus 11.1 sp1 and that had the DEDICATED_MULTIPLIER_CIRCUITRY parameter in there but the implementation wasn't greyed either.- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
Could you please post up your VHDL? I'd like to try editing my file to see if that works.
Thanks in advance.- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
Thanks, that's very interesting. I'll see what happens.
- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
Oliver, which device are you targeting? the CIVGX15 does not have hard multipliers
- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
My device is an EP4CGX22
- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
Editing the vhdl to add the hint didn't make any difference at all :(
- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
Which version of Quartus are you using?
- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
11.1 Web edition
- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
I've learnt that Quartus does something different when you use an lpm_mult to square a number. It works for me when multipying by a constant!
- Subscribe to RSS Feed
- Mark Topic as New
- Mark Topic as Read
- Float this Topic for Current User
- Bookmark
- Subscribe
- Printer Friendly Page