2. p1500-wrapper _creation

5/23/2018 2. P1500-Wrapper _creation

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Automating P1500 Wrapper Creation for

System-on-Chip (SoC).


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Abstract

One of the major efforts of System on Chip (SoC) design is

integrating the Intellectual Property (IP) and verifying thecorrectness of the design.

The purpose of this project is to create IEEE P1500 standardwrappers for any given Intellectual Property (IP) andautomating the wrapper creation .

Wrappers are the circuitry added around an embedded coreto facilitate test reuse and to interface between a test accessmechanism (TAM) and the embedded core.


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Phases Of Project

Understanding Boundary Scan architecture

Developing a dummy module with Boundary Scanarchitecture

Understanding P1500 architecture

Learning Perl Scripting language

Automation of P1500 Wrapper Creation


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SoC Test Problems

Mixing technology

Hierarchical cores

Different core providers

IP protection/Test reuse

Expensive and inefficient external ATE(Automatic Test

Equipment)

Long test application time

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P1500 System Architecture

Standardizes the integration of IPs into SoC environment.

Mechanism for testing of core designs within SoC.

Provision of a wrapper on the boundary (I/O terminals) of each core.

A system chip complying with 1500 should contain the following hardwarecomponents

One standard test wrapper for each core

Signal sources and sinks for test pattern provision and reception

On-chip TAM (Test Access Mechanism) to connect the wrapper to the

source/sinks*(In addition to H/W component 1500 architecture uses a test-specific

language called Core Test Language(CTL) to communicate betweencore providers and core users.)


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User-Defined Parallel TAM

TAM source

1500 Wrapper

Core 1

WIR

TAM-in TAM-out

1500 Wrapper

Core N

WIR

TAM-in TAM-out

TAM sink

Chip I/O Chip I/O.

WSO1 WSIN.

Wrapper Serial Controls (WSC)

Wrapper Serial Port

(WSP)

WSI1 WSON

System Chip

P1500 System Architecture


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CORE

WBY

INPUTS OUTPUTS

WSI

WSO

WRCKWRSTN WRAPPER CONTROLSIGNALS

(ShiftWR,

UpdateWR,

CaptureWR)

WRAPPER

BOUNDARY

REGISTER(WBR)

WRAPPER

BOUNDARY

CELL(WBC)

(WRAPPER SERIAL INPUT)

(WRAPPER SERIAL OUTPUT)WIR

SelectWIR

P1500 Wrapper


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Wrapper Components

Chip

Core

WSI

CaptureWR

WRCK

WSO

ShiftWR

I

O

UpdateWR


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Wrapper Cell

Operational events supported by wrapper cell(Type1)CaptureWRShiftWR

UpdateWR

*(Type 2wrapper cell will not have update register)


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CaptureWR

Chip

Core

WSI

CaptureWR

WRCK

WSO

ShiftWR= 0

UpdateWR


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ShiftWR

Chip

Core

WSI

CaptureWR

WRCK

WSO

ShiftWR= 1

DATA0 1 0 11 0 1 0

0 1 0 1

1

0

0

01011

0

1

0

0

1

1

UpdateWR


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UpdateWR

Chip

Core

WSI

CaptureWR

WRCK

WSO

ShiftWR

DATA0 0 0 0

0000

0

0

0

MuxSelect=1

UpdateWR


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Mandatory Instruction

WS_BYPASS:when no operation of that core is required,

1 bit shift path between WSI and WSO,

WS_EXTEST: To test the interconnections betweencores,

Wx_INTEST:To test the correctness of core module,


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Proposed Work

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Core Core with wrapper

Boundary Cell


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Core With P1500 Wrapper

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P1500 Wrapper Module

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Need of automation

Practical cores being used in an SoC will have many

numbers of pins. So to create a wrapper around a real

core will be tiring, cumbersome and time consuming Since there may be any number of cores present in SoC,

again creating wrappers for each core separately will be

time consuming and complex. And it will be difficult to meet

the time-to-market requirement .

With automation we can meet time to market demands.

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Project Work

Automation is being done with help of Perl scripting.

Input files to the Perl script

Core module.v (Which will give information about input and output ports

of core)

Exclude(list of exclude pins)

Output files of script

Wrap.v(Wrapper module)

Top.v(Top module of core with wrapper ) Perl --

Working of wrapper is being tested through simulation. All mandatory

operations( Capture, Shift and Update) were happening properly

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Test case 1

############# io.v ########

module io(a,b,c,d,e,m,n);

input [1:0]a,b;

input c;

output e;

output [1:0]d;

output m,n;

endmodule############ exclude #########

m;

n;

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RTL Schematic for Test case1

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Simulation Output for Test case 1

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Result

Automation of wrapper creation is being tested for many

test cases for both the types of Wrapper boundary cell

types. As we know that P1500 architecture supports different

types of wrapper cell types. This wrapper generation

supports two types of wrapper boundary cells.

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Limitations and Future enhancements

Does not support bidirectional pins.

Current script supports two types of wrapper cells

As part of future enhancement, the same script can bemodified so that it can be used for other types of cells to

create wrapper around the core.

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Thank you

2. p1500-wrapper _creation

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