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Error Cannot Synthesize Dual-port Ram Logic

list marked files in dired in another buffer Glassmapper fields displaying null despite correct item ID Locker Service: How to get the event target? Nonetheless, if you try to run this code through XST, it will happily infer a BRAM: Synthesizing (advanced) Unit . More tweaking may be required, or manual instantiation of the desired primitive. I use wrappers around everything that is vendor specific. this contact form

Who is this Voyager character? A read/write on one port and a write operation from the other port at the same address is not allowed. That's not supported. I'm not saying that this is the exact reason why it is giving up, but it should be clear that the compiler would have difficulties filling in the blanks for the this page

ACTION: Remove any asynchronous or synchronous clear or reset logic associated with the RAM. Do humans have an ethical obligation to prevent animal on animal violence? So, if there is any risk that your design may attempt to access the same (or similar) address simultaneously from two different clock-domains (with at least one of those accesses being i also have checked the results on scope, and it appears that when i flash the fpga with any of the above configurations, it results like the pins of fpga change

  • Its not giving me the same result.
  • You should check in the Cyclone III hardware manual, if your intended configuration is feasible with this FPGA.
  • To work around it, try creating a variable (or signal) that is purely RAM output (not necessarily valid), and separate logic to blank it when desired, rather than doing both tasks
  • Can you offer any thoughts or comments on this?

How to decline a postdoc interview if there is some possible future collaboration? Good work! Register Help Remember Me? block RAMs) should: be portable between devices from a particular vendor (e.g.

It will be up to you to modify your other logic to behave correctly. If this restriction is ignored, a read or write operation will produce unpredictable results. Xilinx only supports byte-enables on single-port memories. This lets you create a quad-ported 64×1-bit or 32×2-bit distributed RAM in a single slice (use more slices for wider memories).

What is not possible is setting the read/write before write/read behaviour by using a shared variable (whereas you can with other other brand). With Xilinx's tools, you can globally control inference for various classes of primitives (block RAMs, multipliers, shift-registers, etc.) through synthesis options. The mode setting of the read-port does not affect this operation. ACTION: If you intend to infer the RAM into the hardware, refer to Chapter 6, "Recommended HDL Coding Styles," in the QuartusII Handbook, vol. 1., for examples of coding styles that

See also: zet.aluzina.orgEnd user forums for Zet Login Register FAQ Search It is currently 08 Nov 2016, 21:08 View unanswered posts | View active topics Board index All More about the author memory depths being powers of two). This can cause longer compilation time or result in insufficient memory to complete Analysis and Synthesis That seems that I cannot fit anymore the design. For example, Altera specifies the undefined mixed-port read-during-write behavior thusly: For mixed-port read-during-write operation with dual clocks, the relationship between the clocks determines the output behavior of the memory.

Refer to Chapter 7, "Recommended HDL Coding Styles," in the QuartusII Handbook, vol. 1., for examples of coding styles. weblink Altera seems to only support inferring write-first behavior on dual-clock RAMs, but they do support inferring both behaviors on single-clock true dual-port RAMs. Azhar says: 2013-05-31 at 12:15 Sorry, just realized that that is exactly what you were alluding to in your comment too :) Balaji says: 2011-03-15 at 18:31 Hi, If you can For example, with an M9K in simple dual-port mode, you can have a 36-bit read port and a separate 36-bit write port.

On a side note: to avoid all the stuff you get with the megawizard, instantiate rams directly in your code. Realize that to infer the ram, it must also infer a few signals and their values, one of which is the address input. Info: Inferred 1 megafunctions from design logic Info: Inferred altsyncram megafunction from the following design logic: "mem~0" Info: Parameter OPERATION_MODE set to DUAL_PORT Info: Parameter WIDTH_A set to 72 Info: Parameter navigate here Xilinx supports inferring all 3 read/write synchronization behaviors: write-first, read-first and no-change; or "new data" and "old data" read-during-write behavior in Altera parlance (Altera doesn't explicitly call out a no-change analogue,

Altera supports byte-enables on both simple and true dual-port memories. You can control all the paramters yourself. This unknown value may be the old or new data at the address location, depending on whether the read happens before or after the write.

Without more concrete assurances from Xilinx, however, you wouldn't want to rely on this behavior.

Please do reach me at my mail id. One would expect, it has been ever tested before. This code contains some constants describing the FPGA type that is used. Yes, it is pretty good parametrized.But i encoutered this problem:The compilation in Quartus II has stopped after this message -Error: Cannot synthesize dual-port RAM logic "yadmc:SDR_controller|yadmc_dpram:cacheline2|storage"Is this of some incorrect setup,

I can only wirite VHDL, so I can speak only for that. The time now is 11:08 AM. XST supports 2 different coding styles: one is newer, and recommended for Virtex-6/Spartan-6 series devices (but doesn't work on older devices); the other is older and works on all devices (but his comment is here I haven't managed to find any explanation for this tip.

library ieee; use ieee.std_logic_1164.all; use ieee.std_logic_unsigned.all; entity bram_tdp is generic ( DATA : integer := 72; ADDR : integer := 10 ); port ( -- Port A a_clk : in std_logic; Your cache administrator is webmaster. When one port performs a write operation, the other port must not read- or write- access the same memory location. You can have quartus infer a simple dual port ram (with write/read on clock1 and read only on the other clock2) but not write from both.

Figuring out exactly the right sort of Verilog to get multiple tools to infer the block you want can be even trickier. It doesnt just "flash a ram", the entire chip is saved in flash. Spartan 6 to Cyclone III), and even be portable to vendor-independent environments (e.g. Is there a bug on the compiler or I'm doing something wrong?

There are yet more caveats.. Reply With Quote September 23rd, 2010,07:04 AM #4 Tricky View Profile View Forum Posts Moderator **Forum Master** Join Date Oct 2008 Posts 5,137 Rep Power 1 Re: True Dual Port Ram Thanks, Balaji Reply Dan says: 2011-05-03 at 22:34 I'm not familiar enough with Altera tools to give you a specific answer. thanks for your time.

I don't believe this. RAMB16BWER when both ports are 18 bits wide or smaller: A13–A6, including A4, cannot be the same. Which is, perhaps, a little bit silly - considering that the whole point behind this little exercise is to be able to write code that isn't tied to any particular tool, Just include the library in your file: library altera_mf; use altera_mf.altera_mf_components.all; then browse to this directory in your quartus installation: /quartus/common/help/webhelp/master.htm#mergedProjects/hdl/mega/mega_list_mega_lpm.htm For Quartus releases pre v10.0, you could link to this

This applies for both TDP and SDP modes.

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