P1801 – Merging of Power Domains

1. P1801 – Merging of Power Domains Gary Delp

2. Purpose • Provide motivation for the provision of a command in 1801 to merge power domains Outline • 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

3. 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

4. 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 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 mergedinto the parent domains. Draft - proposal provided to P1801 (and other groups) by LSI - #include <std/disclaimer.h>LSI Confidential

5. 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

6. 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

7. 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