Cadence® system design and verification solutions, integrated under our System Development Suite, provide the simulation, acceleration, emulation, and management capabilities.
System Development 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.
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.
Get the most out of your investment in Cadence technologies through a wide range of training offerings.
This course combines our Allegro PCB Editor Basic Techniques, followed by Allegro PCB Editor Intermediate Techniques.
Virtuoso Analog Design Environment Verifier 16.7
Learn learn to perform requirements-driven analog verification using the Virtuoso ADE Verifier tool.
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 technlogy. 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.
I wrote a program that returns incorrect results with large data sets. If the input data set is above a certain size, I see a negative result and the mathematical result can never be negative.
In one example, I get a correct result of 1176350207. But when the result should be2407905288, I instead get -1887062008. I suspect the problem is due to being unable to specify data type (as far as I know) and SKILL is apparently using signed int as defualt (at least for an integer variable). Note that:
log2(1176350207) = 30.13, requires 31 bits to represent
log2(2407905288) = 31.17, requires 32 bits to represent
If I could use an unsigned int, I should be able to represent 2407905288. I've never had a problem letting SKILL do it's dynamically typed goodness before. Perhaps sxtd() or zxtd() could help as they seem to be along the right track, but I don't understand (I'm a programming dunce).
So is there any way to specify variable data type in SKILL? Or am I out of luck with numbers this large?
I raised a service request on this in 2010 (SR 42278266 CCR 846991 Large number multiplication error)
This was part of the response:
The service request example is using a list “signed int” type which corresponds to a 32bit internal number.
220000000 is 0x0D1CEF00 in hex (28 bits set)
220000000*10 = 2200000000 or 0x83215600 (32 bits set)
An overflow occurs because the MSB is set which turns the number into a negativevalue.
To evade this problem, we could use a list double type which has the range needed but would have the following problem:
- checking for overflow or underflow if we are converting back to an int type.
- We can accommodate the approximation of floating point numbers on digital computers and
axlGeoEqual can help with this.
However, the SR was closed with no commitment to fix the problem. I have got used to working around the problem by ensuring that my code doesn't use such large integers.
Due to the danger of overflow, you should consider doing any math that involves multipication or division in floating point. If you need to convert back to integer at the end of the operations to address overflow, underflow, or rounding use the API round(x_float) --> x_int