CF Interface SRAM Tester Cyber Formosa -link all together-

CF Interface SRAM Tester Cyber Formosa

-link all together-

Worker Ownership• Chin-Hua Tsai CEO & Tester Programmer

B95902064 蔡青樺

• Ming-Hen Tsai COO& Interface ProgrammerB95902028 蔡明亨

• Chia-Hua Ho CTO & Interface ProgrammerB95902082 何家華

• Sang-Chang Hong CIO & Tester Programmer & SpeakpersonB95902004 洪三權

WEB SITE• http://peanuts.csie.ntu.edu.tw/~scan33/

study/dsd/final/

Outline

• Introduction

• Why SRAM Tester?Market? Promising Future?

• Technical Difficulty?

• Technique

• What is cf interface?

• How to detect errors?

Outline

• Introduction

• Why SRAM Tester?Why SRAM Tester?Market? Promising Future? Market? Promising Future?


• Technique



What is SRAM Tester?

SRAM

• Static Random Access Memory

• Doesn’t have to periodically refresh

• Used in Cache, SD card... .

SRAM

C-LCM

CFInterface.

Tester

CF Interface SRAM Tester with C-LCM

Multiple Applications Market

• i-Ntelligent

• Dram Tester

i-Ntelligent

• Phone self-Repair

• Test and Repair only one click!

i-Ntelligent

• S: Useful, Safer. For Business!

• W: Undeveloped User Pattern

• O: A new World! Blue Ocean!

• T: Need more capital.

DRAM Tester

• Tester for DRAM

DRAM Tester

• S: 力晶、茂德、南科、華邦 -> 20% Market Share RateDRAM need newest Tech !

• W: DRAM Winter...

• O: 12/16 經濟部紓困方案 Windows 7

• T: Big Monster: SamSung

Outline

• Introduction


• Technical Difficulty?Technical Difficulty?

• Technique



• 1981 年，微軟創辦人比爾．蓋茲（ Bill Gates ）：「個人電腦記憶體需求將不會超過 640KB 」（ Nobody would ever need more than 640KB of memory on theirpersonal computer ）

Diffculty of Testing

• Ram become bigger and bigger

EXPONENTIALLYEXPONENTIALLY!

• Ram Fault become more complexcomplex

• However, required testing time is same.....

Memory Importance

Glowing of RAM...

Terrible Time Complexity

冏From 商湯 to 21th centry...

Outline

• Introduction



• Technique

• What is cf interface?What is cf interface?


What is CF Interface?

• What is CF?

• How does CF work?

• How to use it?

• What have we done?


• What is CF?


• How to use it?


Introduction (by SPEC):

• CF/CF+ cards

• Vendor-independent specification

• CF Storage Cards provided the capability to easily transfer all types of digital information and software between a large variety of digital systems.


• What is CF?


• How to use it?


SPEC focus

• Card Physical

• Electrical Interface

• Metaformat(Information structure)

• Software Interface

• CompactFlash Adapters

Card physical

Card physical

Card physical

2 rows – 1 row 25 pins

Card physical

Card physical

PIN 腳的長短安排 , 可維持插入及拔出的 order

Electrical Interface



Software Interface• The standard PC-AT disk I/O address

spaces 1F0h-1F7h, 3F6h-3F7h (primary) or 170h-177h, 376h-377h (secondary) with IRQ 14 (or other available IRQ).

• Any system decoded 16 byte I/O block using any available IRQ.

• Memory space.

Software Interface• Upon receipt of a Class 1 command, the

CompactFlash Storage Card sets BSY within 400 nsec.

• Upon receipt of a Class 2 command, the CompactFlash Storage Card sets BSY within 400 nsec, sets up the sector buffer for a write operation, sets DRQ within 700 μsec, and clears BSY within 400 nsec of setting DRQ.

• Upon receipt of a Class 3 command, the CompactFlash Storage Card sets BSY within 400 nsec, sets up the sector buffer for a write operation, sets DRQ within 20 msec (assuming no re-assignments), and clears BSY within 400 nsec of setting DRQ.

Software Interface


• What is CF?


• How to use it?


How to use it?• STB_I -STSCHG (PC Card I/O Mode)

Status Pin 46

• WE_I -Write Enable Pin 36

• ACK_O -Acknowledgment Pin 43

• DAT_O -Data Pin 31,30,29,28,27,49,48,47,6,5,4,3,2,23,22,21

Read

• --set modeSTB_I <= '1';WE_I <= '0';-- wait till the ackwait until rising_edge(ACK_O);read_from_the_controller <= DAT_O;

-- read dataportwait until rising_edge(CLK_I);

Write

• STB_I <= '1';WE_I <= '1';--set modeDAT_O <= data_to_controller;--set datawait until rising_edge(ACK_O);-- operate synchronouslywait until rising_edge(CLK_I);


• What is CF?


• How to use it?


Outline

• Introduction



• Technique


• How to detect errors?How to detect errors?

How to detect Errors?

• Detection :All subtypes and All positions of subtype

• Category of Faults

• Detection Algorithm

What kinds of Errors?

• AF ( Address Fault )

• SAF ( Stuck-at Fault )

• TF ( Transition Fault )

• SOpF( Stuck-Open Fault )

• CF ( Coupling Faults )

• DRF( Data Retention Fault )

Address Fault• Case 1: No cell can be access with certain

address

• Case 2:An address can access multiple cells

• Case 3:A cell can be accessed with multiple addresses

• Case 4:Certain cell can be accessed with their own and other address

Stuck-at Fault

Transition Fault

Stuck-open Fault

• Cannot Access Ram

• Due to WL open

• result:SAF0SAF1Random

Coupling Fault

• 當 a-cell 改變， V-cell 就很衰的跟著變

• CFid e.g. <↑;1>

• CFst e.g. <0;1>

• CFin e.g. <0;x> (DRAM)

Data Retention Fault• A cell cannot retain it’s

logic value

• After a time delay Del(100ms < Del < 500ms)the cell will flip

• <1T/ 0> or <0T/1>

Detection Algorithm

• Scan ( Zero-One )

• CheckerBoard

• GALPAT

• Walking 1/0

• March

• Pseudo-Random Test

Scan( Zero-One )

Algorithm:

Step1:write 0 in all cellsStep2:read all cellsStep3:write 1 in all cells Step4:read all cells

Time Complexity:O(n)

Scan( Zero-One )

• Not all AFs will be detected

• SAFs will be detected when it can be guaranteed that the address decoder is correct

• Not all TFs are detected

• Not all CFs will be detected

Check-Board

Step 1: w1 in all cells-W w0 in all cells-BStep 2: read all cells Step 3: w0 in all cells-W w1 in all cells-BStep 4: read all cells

Check-Board


• SAFs will be detected when it can be guaranteed that the address decoder is correct

• Not all TFs are detected


GALPATAlgorithm

Step1: 將所有的 cells 填 0 (or 1), 並定一個base-cell 1(or 0 相對於其它 cells)

Step2: 將所有資料 read 出來， read 完其它的cell 一次就須馬上 read base-cell

Step3: 重覆 Step1,Step2, 將 base-cell 依序移到下一個位置 , 直到 base-cell 都出現過每個 cell

Step4: 將 base-cell 和其它的 cell 資料互換( 即 0->1,1->0), 重覆 Step1,Step2,Step3

Time Complexity:O( n^2)

GALPAT

• All AFs are detected and located

• All SAFs will be located

• All TFs are located

• All CFs are located

Walking 1/0Algorithm

Step1: 將所有的 cells 填 0 (or 1), 並定一個base-cell 1(or 0 相對於其它 cells)

Step2: 將所有資料 read 出來， base-cell 最後才 read

Step3: 重覆 Step1,Step2, 將 base-cell 依序移到下一個位置 , 直到 base-cell 都出現過每個 cell

Step4: 將 base-cell 和其它的 cell 資料互換( 即 0->1,1->0), 重覆 Step1,Step2,Step3

Time Complexity:O( n^2)

Walking 1/0

• All AFs are detected and located

• All SAFs will be located

• All TFs are located

• All CFs are located

Sliding Diagonal

Algorithm

Step1: 把對角線當作 base-cells, 將 base-cells 填 1, 其餘 cells 填 0Step2: Read all cellsStep3: 把所有 base-cells 右移一格 , 回到Step2, 直到所有 base-cells 重回對角線Step4: 將 Step1 的 base-cells 改為填 0, 其餘 cells 填 1, 重覆 Step2~Step3

Sliding Diagonal

• Time complexity = O(n1.5)


• All SAFs are detected and located

• All TFs are detected and located


Butterfly

Algorithm

Step1: 自訂一個 base-cell, 將 base-cells 填 1, 其餘 cells 填0Step2: Read 在 base-cell 上下左右第 1,2,4,8,...(2n) 位置的 cellsStep3: Base-cell 依序在 memory 中移動, 並執行 Step2, 直到 memory 中每一個 cell 都當過 base-cellStep4: 將 Step1 的 base-cells 改為填 0, 其餘 cells 填 1, 重覆Step2~Step3 B: base-cell

N: 北方S: 南方E: 東方W: 西方X: 被重覆標記的 cell

Butterfly


• All SAFs are found

Time complexity = O(n log2 n)

March TestMAT+ Algorithm

↕(w0); ↑(r0,w1); ↓(r1, w0)

Step1: write 0 to all cellsStep2: for( begin to end) read 0 ; write 1;Step3: for( end to begin)

read 1; write 0;

Time Complexity:O( n)

March Test

• MAT+

• AF

• SAF

March TestMATS : ↕(w0); ↕(r0,w1);↕(r1) MATS+: ↕(w0); ↑(r0,w1);↓(r1,w0) Marching 1/0 :↕(w0);↑(r0,w1,r1);↓(r1,w0,r0);↕(w1); ↑(r1,w0,r0);↓(r0, w1, r1); MATS++ : ↕ (w0);↑(r0,w1); ↓(r1,w0,r0); MARCH X : ↕(w0);↑(r0,w1); ↓(r1,w0); ↕(r0) MARCH C :↕(w0);↑(r0,w1);↑(r1,w0);↕(r0);↓(r0,w1);↓(r1,w0);↕(r0);

March Test

MARCH A : ↕(w0); ↑(r0,w1,w0,w1);↑(r1,w0,w1);↓(r1,w0,w1,w0);↓ (r0,w1,w0); MARCH Y : ↕(w0);↑(r0,w1,r1); ↓(r1,w0,r0); ↕(r0) MARCH B : ↕(w0);↑(r0,w1,r1,w0,r0,w1);↑(r1,w0,w1); ↓(r1,w0,w1,w0);↓(r0,w1,w0 )

March TestMarch Algorithm Test Lenth Fault

MATS 4n Some AFs, SAFs

MATS+ 5n AFs, SAFs

Marching 1/0 14n AFs, SAFs, TFs

MATS++ 6n AFs, SAFs, TFs

March X 6n AFs, SAFs, TFs, Some CFs

March C- 10n AFs, SAFs, TFs, Some CFs

March A 15n AFs, SAFs, TFs, Some CFs

March Y 8n AFs, SAFs, TFs, Some CFs

March B 17n AFs, SAFs, TFs, Some CFs

Pseudo-Random Test

• complexity: O(kn)

• k: # of iteration

• it can be designed to detect different types of fault.

Pseudo-Random Test (cont.)

e: escape probability

PD: probability of detecting fault

PD = 1 – e

we want to decrease the value of e


For example:

we want to detect SA0 fault based on Markov chain


S0: state in which a 0 is stored

S1: state in which a 1 is stored

SD0: state in which SA0 fault is detected

(terminate state)

pSx(t): probability of being in state Sx at iteration t

pI1: probability of being in state 1 at first


initial condition:

pS0(0) = 1 – pI1

pS1(0) = pI1

pSD0(0) = 0


A: a false bit

p0: prob of writing 0 to address A

p1: prob of writing 1 to address A

pr: prob of reading address A

Recusive relation:

pS0(t) = (1 – p1) * pS0(t-1) + p0 * pS1(t – 1)

pS1(t) = p1 * pS0(t-1) + (1- p0 – pr)* pS1(t-1)

pSD0(t) = pr*pS1(t-1) + pSD0(t-1)


We want to maximize pSD0(t)

pSD0(t) increase with iteration t

given a escape probability, can we find t?

(e ≥ 1 - pSD0(t))


What's the value of PSD0(t) for any t?

(so we can find t for every given e)


We can use generating function and solve the recursive relation. And blah blah...


T0(e), called test length, is the iteration we need, such that

1 – pSD0(T0(e)) ≤ e

The answer is......

CF Interface SRAM Tester Cyber Formosa -link all together-

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