Cadence® system design and verification solutions, integrated under our Verification Suite, provide the simulation, acceleration, emulation, and management capabilities.
Verification Suite Related Products A-Z
Cadence® digital design and signoff solutions provide a fast path to design closure and better predictability, helping you meet your power, performance, and area (PPA) targets.
Full-Flow Digital Solution Related Products A-Z
Cadence® custom, analog, and RF design solutions can help you save time by automating many routine tasks, from block-level and mixed-signal simulation to routing and library characterization.
Overview Related Products A-Z
Driving efficiency and accuracy in advanced packaging, system planning, and multi-fabric interoperability, Cadence® package implementation products deliver the automation and accuracy.
Cadence® PCB design solutions enable shorter, more predictable design cycles with greater integration of component design and system-level simulation for a constraint-driven flow.
An open IP platform for you to customize your app-driven SoC design.
Comprehensive solutions and methodologies.
Helping you meet your broader business goals.
A global customer support infrastructure with around-the-clock help.
More Support Log In
24/7 Support - Cadence Online Support
Locate the latest software updates, service request, technical documentation, solutions and more in your personalized environment.
Cadence offers various software services for download. This page describes our offerings, including the Allegro FREE Physical Viewer.
The Cadence Academic Network helps build strong relationships between academia and industry, and promotes the proliferation of leading-edge technologies and methodologies at universities renowned for their engineering and design excellence.
Participate in CDNLive
A huge knowledge exchange platform for academia to network with industry. We are looking for academic speakers to talk about their research to the industry attendees at the Academic Track at CDNLive EMEA and Silicon Valley.
Come & Meet Us @ Events
A huge knowledge exchange platform for academia. We are looking for academic speakers to talk about their research to industry attendees.
Americas University Software Program
Join the 250+ qualified Americas member universities who have already incorporated Cadence EDA software into their classrooms and academic research projects.
EMEA University Software Program
In EMEA, Cadence works with EUROPRACTICE to ensure cost-effective availability of our extensive electronic design automation (EDA) tools for non-commercial activities.
Apply Now For Jobs
If you are a recent college graduate or a student looking for internship. Visit our exclusive job search page for interns and recent college graduate jobs.
Cadence is a Great Place to do great work
Learn more about our internship program and visit our careers page to do meaningful work and make a great impact.
Get the most out of your investment in Cadence technologies through a wide range of training offerings.
Overview All Courses Asia Pacific EMEANorth America
Instructor-led training [ILT] are live classes that are offered in our state-of-the-art classrooms at our worldwide training centers, at your site, or as a Virtual classroom.
Online Training is delivered over the web to let you proceed at your own pace, anytime and anywhere.
Exchange ideas, news, technical information, and best practices.
The community is open to everyone, and to provide the most value, we require participants to follow our Community Guidelines that facilitate a quality exchange of ideas and information.
It's not all about the technology. Here we exchange ideas on the Cadence Academic Network and other subjects of general interest.
Cadence is a leading provider of system design tools, software, IP, and services.
Hi All,I have a design that have some bidirectional signals, driven one side by Verilog Module, next side by SV testbench.But signals should have a functionality of wand (wire-and) type onlyBoth are interacting through SV Interfaces only.Three combinations I tried:
Or putting in simple terms, How to assign values to wire signal types of interface from a class object ??i.e. how to make it possible to change class_intf_inst.a =0; by calling the function p.change_interface();As it is giving the error This or another usage of 'class_intf_inst.a' inconsistent with 'net' objectsample code is:interface intf( input logic clock); wand a,b;endinterfaceprogram main (intf intf_inst); int count =0; class packet; virtual intf class_intf_inst; function new (virtual intf intf_inst); class_intf_inst =intf_inst; endfunction task change_interface; class_intf_inst.a =0; endtask endclass packet p =new (intf_inst); initial begin while (1) begin #15; $display ( "program a = %b, b = %b ",intf_inst.a, intf_inst.b); p.change_interface(); count = count +1; if (count >1000) $finish; end end assign intf_inst.b = count; assign intf_inst.a = 1'b1;endprogramtask indp_task;endtaskmodule top; reg data_value, clock; intf intf_inst (clock); main m(intf_inst); initial begin clock =0; forever begin #10 clock = ~clock; $display (" top a = %b, b = %b ",intf_inst.a, intf_inst.b); end endendmodule
Even though this is SystemVerilog, you still have to deal with some of the restrictions enforced by the underlying Verilog language itself. In that language, you cannot make behavioral assignments directly to a "net" type. A net type like wand can have multiple drivers. You can only make behavioral assignments to a single driver of the net. Then Verilog will resolve the multiple drivers into their final value.interface intf( input logic clock);wand a,b;logic b_driver;assign b = b_driver;modport port (inout a,b);endinterfaceprogram main (intf intf_inst); int count =0;initial begin while (1) begin #10; intf_inst.b_driver = 1'b1;If you truely wanted the port to be bidirectional, you might want to put a control on the behavioral driver you are creating:interface intf( input logic clock);wand a,b;logic b_driver,b_ctrl;modport port (inout a,b);assign b = b_ctrl ? b_driver : 'bz;endinterface
Thanks Tam for your information. But in this case we are increasing the no. of wires in the interface (as we are adding logic type signals to be driven by SV TB), which is not according to the standard or specification.Any turn-arounds for it ?RegardsMayank
If you can't instantiate the external driver in the interface (which is a resonable restriction), then you'll have to instantiate it elsewhere, probably in the block that describes the dut's environment. This works:interface intf( input logic clock);wand a,b;modport port (inout a,b);endinterfaceprogram main (intf intf_inst); int count =0;initial begin while (1) begin #10; intf_inst.b = 1'b1; count = count +1; if (count >1000) $finish; end endendprogrammodule top; reg data_value, clock; intf intf_inst (clock); main m(intf_inst.port); assign intf_inst.a = data_value; initial begin clock =0; forever begin #10 clock = ~clock; end endendmodule% more testit.svinterface intf( input logic clock);wand a,b;modport port (inout a,b);endinterfaceprogram main (intf intf_inst, output logic b_driver); int count =0; initial begin while (1) begin #10; b_driver = 1'b1; count = count +1; if (count >1000) $finish; end endendprogrammodule top; reg data_value, clock; // External drivers for bi-directional pins logic b_driver; assign intf_inst.b = b_driver; assign intf_inst.a = data_value; intf intf_inst (clock); main m(intf_inst.port,b_driver); initial begin clock =0; forever begin #10 clock = ~clock; end endendmodule
Nice SuggestionThanks RegardsMayank
Oops, sorry about the double post of the original source code there.
Fine. Do we have to keep
passing this output logic b_driver, all the way to class object instances and thier functions.
For small designs its OK, but for bigger designs and testbenches, it will
become too cumbersome. Where you are assigning by multiple object
Any turn around for this ??
Oops sorry !! for triple post, including this post.
I'm sorry that you find this burdensome. But it is the way that the Verilog language works. If you have multiple drivers on a net, you will have to describe each of them and assign their values separately. You are going to have to "keep passing" something around to the different blocks of code that can change the driver's value. How does it differ between passing the resolved net or its external driver?