Honored ContributorHi everyone,
I'm new at the Altera Forum and I'm also a newbie in using Altera FPGAs. In order to design a packet filter for a DVB application, I'm looking for a solution to implement a CAM (Content Addressable Memory) on a Cyclone-III FPGA. Can anyone help me with that? Thanks in advance Modellpilot
Honored Contributorspeak out ur deign spec such as 512x32bit,dual port,dual clock.
In Quartus, it's easy to realize by using megawiard tool!Honored ContributorSorry, but I think there is a missunderstanding: I'm looking for a CAM not for a RAM :cool:
I allready had a look on Quartus. And Yes, the MegaWizard Plug-In Manager provides a lot of different memory controllers (single/dual-port, single/dual-clock, RAM/ROM/SREG). But CAMs are only supported when using an APEX device. When selecting a Cyclone-III CAMs and Flash Memory is disabled :mad: ModellpilotHonored ContributorWhat size do you want? What speeds? Is it Ternary(this is often a deal-breaker for larger CAMs, unless you don't mind using a ton of resources). There's a nice trick for making binary CAMs out of RAMs. I have a parameterized VHDL design for it, but I wrote it a few years ago and it targets either M4Ks or M512s. I can modify it for M9Ks, or might post-it as is for now, but am curious what your requirements are, as it might not work for you.
Honored ContributorI need a 24x12 CAM (means 5-bit address and 12-bit word size). It would be great if you could help me with a VHDL code :)
A version for M9Ks would be fine. But I think it is no big deal to adapt an example for M4Ks. Right? Thanks in advance!Honored ContributorAn M9K can do a 32x8 CAM, so you'll basically change the parameters in M9K_CAM.vhd to do a 32x16 CAM(it needs to be a multiple of these dimensions), and then just tie off the extra ports. I built this quickly but believe it is correct. There is a presentation that is very old on this topic(it was done as Stratix was rolling out). I have a document that refers to it, so together you can use them for understanding. (Not the most professional delivery, but hey, if it works.) You can also just use the M9K_CAM.vhd and M9K.vhd files and just play with it yourself.
Honored ContributorHello,Modellpilot
I misunderstood u and you can find a 256x8 CAM in http://www.geocities.com/deepakgeorge2000/cam.htm (http://www.geocities.com/deepakgeorge2000/cam.htm) with VHDL code.Hope can help you.Honored ContributorGreetings,
I have a problem filling the CAM with data ,does anybody know how I can initialize the CAM using the initial file ?or is there any other way ? please help me, Many thanks in advanceHonored ContributorHi mehryar,
unfortunately I can't help you regarding a question about the models of Rsyc or markman. After all I analyzed the usefull hints and realized a custom CAM implementation which is appropriate to the dedicated requirements of my application. Best regards, Modelpilot!Honored ContributorHi modelpilot,
Did you write your own CAM from scratch? or you used the CAM provided from RYSC? either ways can you send me your design ,if it is possible. I tried both the fast CAM from altera and parameterized CAM by RYSC but still I don’t know how to initialize it!Honored ContributorHi mehryar,
yes I wrote my CAM from scratch. Because the application required a very high performance for a dedicated context-specific filtering. Due to the use of this model in one of our products, I can't send you my design. Sorry! Modelpilot
