( ESNUG 505 Item 5 ) -------------------------------------------- [05/24/12]
From: Jacob Rael <jjrael=user domain=broadcom not calm>
Subject: Broadcom on IC Manage for DM, IP reuse, bug tracing, tool speed-up
Hi, John,
In late 2011, three different groups inside Broadcom independently evaluated
multiple design data management vendors.
1st digital group - to replace internal scripts.
2nd digital group - to replace prior commercial DM system.
custom analog group - to replace prior commercial DM system.
Each group ultimately selected IC Manage's GDP. Here's why each chose GDP;
based on DM, IP reuse, bug management, and security.
1. Multisite collaboration
Broadcom development groups provide macros to other internal groups.
(Our 1st digital group was managing their macros with scripts and
utilities based on an open source DM. To eliminate the required
ongoing development and maintenance costs is why they evaled GDP.)
One of the advantages of IC Manage is its multisite capability. For
example, we can easily add cache to remote sites to improve performance.
With IC Manage, we can easily distribute data globally.
2. Branching
GDP has straightforward branch management. It takes only 10 minutes to
set up a branch. The process of creating a branch consists of defining
the name of the branch and the content to include. To merge branches,
we push the "update child" or "update parent" button.
We can use GDP to track down the history of individual files or lib/data
types from the beginning of the project. IC Manage can easily restore
any past state to recover from design mistakes. If our users want to
execute a set of actions or build a report, they can choose to perform
these actions through the GUI or through a script using the CLI.
3. Performance
Another advantage of GDP is its workspace synchronization performance.
Below is a sync test by our second digital group; their test contained
a complete hierarchical schematic and layout database, including std
cell libraries. The depot & workspace files were located on separately
mounted network disks. It took 11 minutes to checkout the entire
database into an empty user workspace using GDP. The incremental
check-outs and check-ins were pretty much instantaneous.
2.5 GB workspace (77,000 files) ICM GDP sync time 11 minutes
We recently initiated a performance test on our custom analog group's
project. A 16 GB workspace was created to test the workspace sync time.
16 GB workspace ICM GDP sync time 5 minutes
Since moving to IC Manage, our workspaces are much smaller because we can
now structure our designs to include exactly what is required. This
improves our sync time.
4. Interfaces
IC Manage has interfaces to support both our digital and analog design
teams - both a command-line interface and a GUI. There is no limitation
on the type of data we can include in the design management tool because
it can be configured. In addition to design data, we can add docs, other
SW that's related to the particular design, Verilog RTL, etc.
5. IP MANAGEMENT
In our custom analog group, users design an IP block, then another team
uses the IP and modifies it. Another team then makes additional changes.
We need the ability to build chips from various IP blocks and track which
chip is used in which specific IP versions.
We also want to track all the bugs for each IP and move them up to the
chip before we tape out. We can do all this in IC Manage. It provides
an easy tracking mechanism for both IP owners and designers to understand
the usage of all IP versions.
IC Manage lets us make virtual copies of the IP which retains its history
and dependencies. We can then track every instantiation of the copy and
its associated properties. Having consistent history across multiple
projects is critical because the person who originally created the IP
doesn't have to actively maintain it.
To update an IP version, we just toggle the release identifier in the
configuration manager.
6. BUG MANAGEMENT
Our design lead engineers need the ability to collect and triage bugs
before tape-out and during lab verification. Designers normally notify
everyone affected when they find a bug, but it is not always that simple.
For example, if you make copies of the design module, you lose the
ability to trace back to the original block.
GDP contains plug-ins for most popular bug tracking systems. Because we
make virtual copies of an IP, we can query for all the bug history of a
specific IP module, and its sub-blocks, versions, and interdependencies.
Because of this, at tape out, we can be sure we are taping out a design
that does not have any known bugs.
7. SECURITY
With IC Manage, security can be managed at the user level. Also, it
lets us define the locations where data can be populated. We like that
flexibility to put data anywhere so we can quickly build and tear down
projects; however, we limit the locations where data can be populated
for security reasons.
BUILDING A NEW PROJECT FOR THE FIRST TIME
My initial test case was to assemble a chip for a virtual tape-out. When
I began I didn't know how to use IC Manage. I partitioned my data, learned
GDP, and configured and assembled our design for an initial tapeout. Next,
I submitted several bugs, fixed them in layout, and executed an all-layers
tapeout. Finally, I created slides documenting all my work.
My total elapsed initial time with IC Manage was only 2 days.
SWITCHING OUR CUSTOM ANALOG DESIGN TEAM OVER TO IC MANAGE
Our analog group had 2 hours of user training on Friday and 2 hours of user
downtime on Monday when we switched from our old system to IC Manage.
After these 4 hours, they were off and running.
IC MANAGE VIEWS - VIRTUAL FILE DISTRIBUTION SYSTEM
One major downside to IC Manage was it populated each workspace with live
copies of the data. Since they do not use soft links, the amount of disk
space that was used can be very large.
IC Manage's fix is its ICM Views -- a virtual file system with local
caching and disk quota management -- which is its "storage acceleration
software". When designers fetch their databases from the server, they
immediately see all their files (and their metadata such as size,
permissions, and timestamps) but they don't up use any disk space because
the files are virtual.
ICM Views has 3 main elements:
a. Disk Space Savings and Storage management
A soft-links approach, reduces the size of your read data by linking
to a mirror on a common network disc. Mirrors can be useful if
everyone points at the same file versions, however, when the data
changes, it is automatically pushed onto users. You can avoid this
by linking to a cache instead, but the disc savings decreases as
users end up referencing different versions of the design. Finally,
with soft links you must pay close attention to your UNIX permissions
to avoid unauthorized access.
ICM Views' virtual files don't have those drawbacks. It allows you to
populate a virtual workspace anywhere, even on the local disk of the
host machine. If files are modified, they can be placed on the
network filer. This lets designers use their local Linux workstations
as "cache disks". They set the limit on workspace size, then ICM Views
rotates the least recently used files to stay within that quota, and
automatically handles the cache management and network connections.
b. "Zero Time Sync" (ZTS)
ICM Views has a feature called Zero Time Sync that lets you sync your
workspaces really fast but without any symbolic link limitations.
We ran a test on ZTS at Broadcom with a 2 GB workspace, and the user
workspace cache set to 1 GB.
IC Manage GDP + ZTS : 15 seconds
c. EDA tool acceleration
ICM Views lets you assign local storage for the reads, and network
storage for the writes. This means input/output-bound EDA apps
can run much faster because data is local to the CPU. (The EDA apps
that I expect to benefit most are ones that do a lot of reads,
because the reads are now limited by disk access speed instead of
network speeds, e.g. layout and DRC runs.) This will make it much
faster to traverse a complex design hierarchy to determine connections.
CONCLUSION
Two of our BRCM groups have each already taped-out chips with IC Manage GDP
and the third is in the process of deploying it. With IC Manage, we can
actually change the way we build chips.
One group's evaluation comment was that IC Manage has a "next-generation"
design management system working. I agree.
- Jacob Rael
Broadcom Irvine, CA
Join
Index
Next->Item
|
|
