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8

In general, you should not be focusing on optimizing the implementation via the source code — the toolchain is much better at that than you are anyway. And specifying individual gates in the source code is pointless on an FPGA anyway — A function like (s_t > 9) becomes a single 4-input LUT in either case. Instead, focus on clarity and readability for ...


5

Depends on the tool and the target architecture. It will sometimes for example infer a DSP48 (Xilinx) but that is not a given and sometimes you will get something built in the fabric (Which generally has a semi dedicated carry chain up a column, so this is quicker then you might expect). Why do you even care as long as it meets timing? If you want a ...


3

If there's one thing that FPGAs are good at, it's lookup tables — both the little LUTs used for logic and the larger block RAMs that can be used as ROMs. In order to avoid falling behind, in the worst case, you need to be able to decode up to 14 input bits (two 7-bit symbols) at a time. A 16k-word (but rather wide) ROM can easily do it in a single clock ...


2

I want to find out what adder(ripple adder, carry look ahead adder etc.) does the operator + in verilog synthesize to when used in design an adder module. The answer will depend on the synthesis target, and potentially also what the optimiser is optimising for. In my experience on Altera FPGAs it will normally be a ripple carry adder, BUT said ripple carry ...


2

The problem here is that the tech stack (knows as a flow) tends to be a trade secret and heavily NDA'd. As a beginner asking an open-ended question, perhaps the most useful answer is a list of places to look for more information. The two big software vendors are Cadence and Synopsys. Both of them offer a full flow from RTL (and earlier) through to the ...


2

I don't think such large ICs are designed directly in Verilog, no more than large software projects are written in assembly. I suspect the big makers, like Intel and AMD, have specialist compiler-like software that generates Verilog from much more high-level descriptions, such as register transfer languages.


1

The key difference in a bit wise operator is that the number of bits has no effect on performance—each bit operation is independent of the other bits. But once you get to arithmetic operators then there is a dependency from LSB to MSB that creates a long timing arc. Updated Answer to an almost entirely different question What you are seeing is a difference ...


1

ram contains 64 memory units, so addr ranges from 0 to 63. A 6-bit wide signal is enough to hold a number from 0 to 63. From ram[addr]<=data; and assign out = ram[addr_reg];, you can see addr represents a binary number. It's not meant to be used as 6 individual signals.


1

BitClk upon which you condition an always block is not a legitimate clock, but a derived signal. In simple terms, Don't do that that. Instead, clock your output registers from an actual clock, using a clock enable. Work out your code such that the I2S data changes based on the source clock, when enabled by a determination that you are at the appropriate ...


1

Ok I solved it. The problem lies in the (wrong) usage of disable iff. As written here: disable iff disables the property if the expression it is checking is active. This is normally used for reset checking and if reset is active, then property is disabled. So it needs a boolean expression to evaluate. In my case, I just removed it and it is now working.


1

Input data per clock cycle : 8 data bit Encoded word length: 1 bit / 4 bit / 5 bit / 6 bit / 7 bit Use a 14 bit register R that holds the 8 code bits from this cycle + 6 bits of any prior partial codes from the prior cycle. The most direct way to process all 14 DATA bits is to use a bunch of block RAMs, with the register serving as a 14 bit address. What ...


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