synthesis

问题 I am currently working on logic synthesis- given a high level description of a hardware I wish to convert it into a circuit of gates,flip flops etc. I am not very much familiar with the theory. I searched the internet, but most of them refer to online book stores. Could someone please refer me to any good tutorials on the net? Any help regarding it would be appreciated. 回答1: A flow primer can be found here: Advanced ASIC Chip Synthesis Using Synopsys® Design Compiler® Physical Compiler® and

问题 I have this function "cost_compare" that I would like to offload on FPGA for some experimental purposes. This function, how it is called and its arguments are as follows. The synthesis tool doesn't accept double pointers as arguments for HW functions (in fact it is very picky about using pointers especially to data structures). How do I get rid of the pointers in the function argument list? In other words, how do I convert pointers in this example to values? How does this possible solution

问题 I synthesized my design with Xilinx ISE 13.1. Target device is Virtex 5. Then I encountered this warning: WARNING:Xst:819 - "F:/FRONT-END/h264/inter/src/eei/eei_mvd.vhd" line 539: One or more signals are missing in the process sensitivity list. To enable synthesis of FPGA/CPLD hardware, XST will assume that all necessary signals are present in the sensitivity list. Please note that the result of the synthesis may differ from the initial design specification. The missing signals are: <mvd_l0<3

问题 My question is regarding the first state used in a synthesized state machine. I'm working with a Lattice iCE40 FPGA, the EDA Playground for simulation and Lattice's Diamond Programmer for synthesizing. In the following example I am generating a series of signals (the example only shows the lines referring to the state machine). This works fine in simulation; i.e. the first case accessed is sm_init_lattice and the required signals are produced). However, the synthesized version goes straight

问题 this is my first post so I hope I'm doing this correctly. I'm trying to output a "4 3 2 1" on a four digit seven segment display on a BASYS2 board. I have checked to make sure that 0 enables the signal and that I have the ports mapped correctly. I believe the error is within my multiplexing logic since I am only able to display a single digit. I'm new to Verilog (am used to C) and would appreciate any suggestions. Thanks `timescale 1ns / 1ps module main (clock, AN0, AN1, AN2, AN3, CA, CB, CC,

问题 Flip-Flops(,Registers ...) are usually triggered by a rising or falling edge. But mostly in code you see an if-clause which uses the rising edge triggering. In fact i never saw a code with falling edge. Why is that? Is it because naturally the programmers use rising edge, because they are used to, or is it because of some physical/analog law/fact, where the rising edge programming is faster/simpler/energy-efficient/... ? 回答1: As zennehoy says, it's convention - but one going back to when

问题 I've gotten in the habit of developing a lot testbenches and use for() and while() loops for testing purpose. Thats fine. The problem is that I've taken this habit over to coding for circuits which should be synthesizable. XST and others refuse to synthesize code (without additional modification to synthesis parameters) such as: while (num < test_number) begin . . . num = num+1; end This is bad coding style because to the synthesizer test_num is an int with value 2^32! or it sees it as

问题 Say I need a signal to represent numbers from 0 to 5; obviously this needs 3 bits of std_logic to be represented ( i.e if MAXVAL=5, then bitwidth= { wcalc "floor(logtwo($MAXVAL))+1" } ). I'm aware I could do: SIGNAL myLogicVector : STD_LOGIC_VECTOR(2 downto 0) := 5; with which I'd explicitly specify an array of three std_logic 'bits', and set initial value; then I could use REPORT to print out the length (in this case, 3): report("Bit width of myLogicVector is "& integer'image(myLogicVector

问题 first time poster here. I usually like to find the answer myself (be it through research or trial-and-error), but I'm stumped here. What I'm trying to do: I'm building a simple android audio synthesizer. Right now, I'm just playing a sine-tone in real time, with a slider in the UI that changes the tone's frequency as the user adjusts it. How I've built it: Basically, I have two threads - a worker thread and an output thread. The worker thread simply fills a buffer with the sine wave data

问题 I'm very new to Objective C. (Two days now). When read about @synthesize , it seemed to overlap with my understanding @property (which I thought I understood) ... So, some details need to be ironed out in my mind ... it's bugging me. Please correct me if I'm wrong about differences of @property and @synthesize : If you declare a @property in your @interface , then you're telling the world that users can expect to use standard getters and setters for that property. Futhermore, XCode will make