Transcript P1801 – Merging of Power Domains

P1801 – Merging of Power
Domains
Gary Delp
Purpose
• Provide motivation for the provision of a command in 1801 to merge
power domains
Outline
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Top down and bottom up flows – agree on terms
Packaged Electronic Design IP in the flow
The command
Before and after state of the data objects
An additional (implicit) data object, the power element collection
Draft - proposal provided to P1801 (and other groups) by
LSI - #include <std/disclaimer.h>LSI Confidential
2
Top down and bottom up flows – agree on terms
• A Top down flow is a flow which starts with the general, and then
through progressive refinement proceeds to the end goal.
– All objects are created within their context
– Advantages:
– Disadvantages:
• A bottom up flow is a flow which starts at the detailed component then
combines fully elaborated components into a design.
– Advantages:
– Disadvantages:
• An IP delivery flow is a flow which supports the development of
components separate from designs (using the IP-XACT component
and design objects, where hierarchy allows components to include
instances of designs, and designs to include multiple (and differently
configured) instances of components. The component is the unit of
delivery.
– Advantages:
– Disadvantages:
Draft - proposal provided to P1801 (and other groups) by
LSI - #include <std/disclaimer.h>LSI Confidential
3
Packaged Electronic Design IP in the flow
• When designing IP (a
component), the assumed
context must be able to be
defined.
– Set port related supply
– The context is a rich one, with
the potential of multiple
domains and control signals
• When the IP (component) is
incorporated into a design,
the elements of the
component will be
incorporated into extent of
the design.
• The domains of the
component may also be
usefully be incorporated into
the domains of the “parent”
design
Draft - proposal provided to P1801 (and other groups) by
LSI - #include <std/disclaimer.h>LSI Confidential
Beautiful Build coming,
watch this space;
it starts out as
An IP block
with 3 domains.
That block gets included
twice in a design
The domains are merged
into the parent domains.
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The command
• Option A is recommended, Option B has been discussed, but
considered dangerous
• Merge_domains –parent_domain XXX –child_domains [YYY, …]
– It is a error if any of the specified power supplies from the child domain are
different than those in the parent domain.
– After the merge command:
• The child domain names remain available for simulation and probing (get) purposes
– A) but refer to the state of the parent domain.
– B) and continue to refer to only the elements of that child domain
• It is an error if subsequent commands attempt to connect power supplies to the
child domains
• Any assignments to the parent domain will have effect over all of the elements
merged.
• (It is an error if any subsequent commands change the value set by earlier
commands (command layering semantics)
– A) All elements in the parent domain share the same supply specifications
– B) The child domain may have different secondary supplies (biases, etc)
from the primary
Draft - proposal provided to P1801 (and other groups) by
LSI - #include <std/disclaimer.h>LSI Confidential
5
Before and after state of the data objects
• Before, child domain is primary domain object
• After, child domain is a
– A) Alias for the primary domain but may not be used to set supplies
– B) a reference to the subset of the elements that came from the child
domain
Draft - proposal provided to P1801 (and other groups) by
LSI - #include <std/disclaimer.h>LSI Confidential
6
An additional (implicit) data object, the power element collection
• Not clear that this object is ripe…
Draft - proposal provided to P1801 (and other groups) by
LSI - #include <std/disclaimer.h>LSI Confidential
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