upf presentation

5/21/2018 Upf Presentation

1/30


2/30

AgendaPower Dissipation in CMOS

Low Power Design Challenges

Introduction to UPF

UPF & CPF

Advantages of UPF

F.I Vs P.I

Low Power Design and Verification Flow

Basic Terminologies

Power Management Architecture & Cells

Power Management Techniques

Implementation of UPF


3/30

Power Dissipation in CMOS


4/30

Low Power Design Challenges


5/30

Basic Idea


6/30

What is UPF?

Unified Power Format

UPF provides the ability for electronic systems to be designed with

power as a key consideration early in the process.

Why UPF?

No existing HDL adequately supports the specification of power

distribution and management.

Vendor-specific formats are non-portable and create opportunitiesfor bugs via inconsistent specifications.


7/30

The Unified Power Format (UPF)


8/30

Working Group Entity Members


9/30

Fast Response to Industry Need


10/30

UPF & CPF :-

These are the two power-formats that are recognized through-out

the industry which specifies power-gating considerations for a design.

Low power Cells which are specified in the UPF or CPF are inserted

separately in the netlist.

Power Compilers (Cadence RC who works on CPF ) and (Synopsys DC

which works on UPF) than reads the power intent and insert the low

power cells in the netlist. Thus at GLS it can be checked that power-

domains are following the power-up and power-down sequence

correctly.

UPFIEEE standard and 1.0, 2.0 are currently available.

CPF Maintained by Si2 group and versions 1.0, 1.0e, 1.1 and 2.0 are

currently available.


11/30

Advantages of UPF:-

>The UPF file is the input to several tools (e.g., simulation,

synthesis, formal verification, and place-and-route tools).

>Synthesis tools can read the RTL/UPF design input files and

produce a netlist.

>The UPF file may be reused without change later in the tool flow.

>A UPF specification can be included with the other deliverables of

intellectual-property (IP) blocks and reused along with the other

delivered IP files.

>The same standard can be used in a multi-vendor tool flow.


12/30

Functional Intent Vs Power Intent


13/30

Low Power Design and Verification


14/30

Few Terminologies :-

Operating corner

Power Domain

Power mode

Power Switch Rule

State Retention Rule

Power Switch Cell


15/30

Power Management Architecture:-

Power States and Transitions

Isolation and Level Shifting

State Retention


16/30

Isolation Cells :-

Isolation cells are typically used to protect logic that is powered onfrom logic that is powered off.

Used to prevent unknown values in unpowered logic from propagating

into live logic

Can also be used to prevent leakage current from live logic from

improperly powering unpowered logic.


17/30

Level Shifters :-

Changes the voltage from one discrete value to another discrete value.

A 1b1 driven by 1.0 logic may be too much for 0.7 logic and likewise a

1b1 from 0.7 logic may not translate into 1b1 for 1.0 logic.

A Level Shifter changes a 0.7V 1b1 so you are propagating valid digitalvalues through the circuit.


18/30

State Retention :-

A Sequential element that can retain its value despite being powered

off.

Useful to recover the last known state of the design when power was

removed.

Reduces the amount of time needed reset a design to a specific state to

continue operation.


19/30


20/30

Power Management Techniques:-

Power Gating

Multi-Voltage

Dynamic voltage and frequency scaling


21/30

Power Gating:-

Power reduction technique to reduce leakage power by shutting-

off , or powering down unnecessary logic.

Can be enabled by power switch or MTCMOS cells.


22/30

Sleep Transistor used in Power Gating


23/30

Multi Voltage:-

Power Saving Technique to operate different logic blocks atdifferent voltages.


24/30


25/30

Bias Voltage:-

Used to change the threshold value of the cell to improve the

leakage characteristics of the cell.


26/30

Dynamic Voltage and Frequency Scaling:-

Power saving technique to change the voltage/or clock frequencywhile the chip is running .


27/30


28/30


29/30

Results


30/30

Multi-Voltage Special Cells Requirement

upf presentation

Documents