1 Overview
1.1 Scope
The format provides the ability to specify the supply network, switches, isolation, retention and other aspects relevant to power management of an electronic system.
Monday, July 26, 2010
Friday, March 5, 2010
UPF1.0 Ch5 Simulation semantics
"During simulation, each supply port and net maintains two pieces of information: a supply state and a voltage value."==>
"The supply state itself consists of two pieces of information: an on/off state and a full/partial
state."==>
"The full/partial state represents the conductance of a switch along the supply path; it is
asserted when the switch is partially on, and de-asserted when it is fully on or fully off."
"The supply state itself consists of two pieces of information: an on/off state and a full/partial
state."==>
"The full/partial state represents the conductance of a switch along the supply path; it is
asserted when the switch is partially on, and de-asserted when it is fully on or fully off."
UPF1.0 Ch4 Power domains, name spaces, and precedence
4.1 Power domains
"In addition to creating the structural grouping of power domains, UPF commands create and connect new objects (switches, supply nets, etc.) that do not exist in the HDL, resulting in two orthogonal structures to the design, the power domain structure and the logic design structure."
"A power domain is a collection of design elements that share a primary power and ground supply net."
"A power domain can be either contiguous or non-contiguous. The power domain is contiguous if going from any object in the extent of the power domain to any other object in the extent does not require leaving that power domain. A power domain is non-contiguous if the extent of the domain needs to be left when connecting supply nets to design elements."
"In addition to creating the structural grouping of power domains, UPF commands create and connect new objects (switches, supply nets, etc.) that do not exist in the HDL, resulting in two orthogonal structures to the design, the power domain structure and the logic design structure."
"A power domain is a collection of design elements that share a primary power and ground supply net."
"A power domain can be either contiguous or non-contiguous. The power domain is contiguous if going from any object in the extent of the power domain to any other object in the extent does not require leaving that power domain. A power domain is non-contiguous if the extent of the domain needs to be left when connecting supply nets to design elements."
UPF1.0 Ch3. Definitions, acronyms, and abbreviations
3.1 Definitions
3.1.10 isolation cell: A design element that passes logic values during normal mode operation and clamps its output to some specified logic value when the control signal is asserted.
3.1.11 level shifter: A design element that translates signal values from an input voltage swing to a different output voltage swing.
3.1.24 regulator: A design element that takes a set of input supply nets and provides the source for a set of output supply nets. The output voltage is a function of combining the input voltage and the logical state of any control signals.
3.1.25 retention: Enhanced functionality associated with selected sequential elements or a memory such that memory values can be preserved during the power-down state of the primary supplies.
3.1.10 isolation cell: A design element that passes logic values during normal mode operation and clamps its output to some specified logic value when the control signal is asserted.
3.1.11 level shifter: A design element that translates signal values from an input voltage swing to a different output voltage swing.
3.1.24 regulator: A design element that takes a set of input supply nets and provides the source for a set of output supply nets. The output voltage is a function of combining the input voltage and the logical state of any control signals.
3.1.25 retention: Enhanced functionality associated with selected sequential elements or a memory such that memory values can be preserved during the power-down state of the primary supplies.
UPF 1.0 Ch1 overview
1.1 Key characteristics of UPF
"UPF provides the ability for electronic systems to be designed with power as a key consideration early in the process."==>
"It accomplishes this through the ability to allow the specification of implementation-relevant power information early in the design process — RTL (register transfer level) or earlier."
(UPF captures the low power design intention and makes sure this intention is carried through the whole design process.)
"A UPF specification defines how to create a supply network to supply power to each design element, how the individual supply nets behave with respect to one another, and how the logic functionality is extended to support dynamic power switching to these logic design elements."
(This statement pretty much summarized UPF's usage)
1.2 Power supply network design intent
"To help manage the complexity of the supply network specification, power domains are defined to group elements from the logic hierarchy that share common supply needs"
(Explaining power domain)
"In addition to the primary supply, UPF provides automation and well-defined semantics for retention and isolation supplies"
"The supply network consists of supply ports, switches, and supply nets. Supply network objects are defined within the context of a power domain. Supply ports provide the supply interface to power domains and switches. Switches control the supply distribution. Supply nets connect supply ports."
"A UPF supply network also defines a directed acyclic graph (DAG)."
"To capture situations which are never intended to occur, UPF also provides the ability to define legal and illegal states using power state tables (PSTs). This PST information can then be used for optimizing the implementation."
"Implementation tools can use that information to infer level shifters wherever a signal crosses from a power domain operating at a voltage level that may be different than the voltage level of another power domain to which it connects."
1.3 Extending logic specification
"Isolation is required to ensure undefined outputs from powered-down design elements do not drain power from those design elements that are not powered down. Isolation also ensures a specific logic value is driven from the power domain’s outputs."==>
"UPF supports the specification of isolation strategies that provide information on the clamp values and location of the isolation logic."
"Retention is the ability to save the value of a sequential element in a power domain prior to switching off the power to that element and then later restoring its value after power has been enabled for the element."
"UPF provides the ability for electronic systems to be designed with power as a key consideration early in the process."==>
"It accomplishes this through the ability to allow the specification of implementation-relevant power information early in the design process — RTL (register transfer level) or earlier."
(UPF captures the low power design intention and makes sure this intention is carried through the whole design process.)
"A UPF specification defines how to create a supply network to supply power to each design element, how the individual supply nets behave with respect to one another, and how the logic functionality is extended to support dynamic power switching to these logic design elements."
(This statement pretty much summarized UPF's usage)
1.2 Power supply network design intent
"To help manage the complexity of the supply network specification, power domains are defined to group elements from the logic hierarchy that share common supply needs"
(Explaining power domain)
"In addition to the primary supply, UPF provides automation and well-defined semantics for retention and isolation supplies"
"The supply network consists of supply ports, switches, and supply nets. Supply network objects are defined within the context of a power domain. Supply ports provide the supply interface to power domains and switches. Switches control the supply distribution. Supply nets connect supply ports."
"A UPF supply network also defines a directed acyclic graph (DAG)."
"To capture situations which are never intended to occur, UPF also provides the ability to define legal and illegal states using power state tables (PSTs). This PST information can then be used for optimizing the implementation."
"Implementation tools can use that information to infer level shifters wherever a signal crosses from a power domain operating at a voltage level that may be different than the voltage level of another power domain to which it connects."
1.3 Extending logic specification
"Isolation is required to ensure undefined outputs from powered-down design elements do not drain power from those design elements that are not powered down. Isolation also ensures a specific logic value is driven from the power domain’s outputs."==>
"UPF supports the specification of isolation strategies that provide information on the clamp values and location of the isolation logic."
"Retention is the ability to save the value of a sequential element in a power domain prior to switching off the power to that element and then later restoring its value after power has been enabled for the element."
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