在傳統的測試方法上，從待測電路(CUT)壓縮測試輸出信號有兩種方法。其中一種方法多輸入簽名暫存器（MISR），已被使用了幾十年。但這個方法是不能有任何的X值進入MSIR。因此，在輸出端需要一個遮罩(mask)去處理X的值。傳統的X遮罩技術，需要很多的資料量加以控制，這些資料量占據了絕大部分的記憶體空間。而本文提出了一種選擇性的X遮罩的編碼，進一步減少了控制碼的資料量。在實驗結果中，掃描鏈反應(scan response)產生了更好的壓縮比(compression ratio)，對於在較長而且X連續性較多的電路裡，減少控制碼的量越明顯，除此之外，此方法所使用的解壓縮硬體可以被運用在任何學術或業界電路中。

Traditionally, the circuit under test (CUT) compression test output signal in two ways. One way, multiple input signature register (MISR) has been used for decades. However, this method can not have any X value into the MSIR. Therefore, the output needs a mask to deal with the X value. Traditional X-mask technology needs a large number of data to control. This paper presents a selective encoding of X mask to further reduce the amount of data of control codes. In the experimental results, the scan response produced a number of better compression ratio (CR), For contain longer and more continuous X circuit, the amount of control code which are reduced more obvious, in addition, the extract hardware can be used in any academic or industry circuits.

內文目錄
中文摘要..................I
英文摘要..................II
內文目錄..................III
圖片目錄..................V
表單目錄..................VI


第一章 序論....................1

1.1 研究背景..............1
1.2 壓縮測試所帶來的挑戰..2
1.3 X訊號處理的技術.......5
1.3.1 過去的技術..........5
1.3.2 現有的技術..........9

第二章 提出的解壓縮硬體及方法..12

2.1 解壓縮硬體架構........12
2.2 提出的解壓縮方法......13

第三章 提出的壓縮方法..........17

3.1 研究動機與想法........17
3.2 壓縮控制碼的演算法....19
3.2.1 定義壓縮狀態........19
3.2.2 壓縮控制碼..........21

第四章 實驗結果................27

第五章 結論....................29

References.....................30

圖片目錄 
圖1.1 測試壓縮架構	3
圖1.2 輸出響應偵錯概念圖	4
圖1.3 XOR TREE基本架構	7
圖1.4多輸入簽名暫存器(MISR)基本架構	8
圖1.5 X-masking基本架構	11
圖2.1 提出的解壓縮硬體架構	12
圖3.1 提出的壓縮程序圖	25
圖3.2 提出的壓縮流程圖	26

表單目錄
表1.1 非X容忍的XOR TREE範例	7
表1.2 輸入簽名暫存器(MISR)起始狀態為0000的範例	8
表1.3 X-masking範例	11
表3.1 控制狀態表	20
表3.2 在正常狀態下原始碼對控制碼的編碼例子	22
表3.3 原始碼未發現X項時對控制碼編碼的步驟	23
表3.4 控制碼編碼後結果不好時的步驟	23
表4.1 工業電路模擬結果	28
表4.2 學術電路模擬結果	28

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