世界上得到視網膜相關疾病的病人，像是老年性黃斑部病變以及視網膜色素病變的人逐年增加，因此近年來有不少研究開發新的治療方法，其中一種方式就是用人工視網膜取代受損的細胞。
本篇完成了視網膜晶片裡的內建時脈控制電路，此控制電路管理了晶片裡所有控制訊號，此架構具有靈活的設計彈性，設計時，若要更改控制訊號的波寬、升起或落下時機是很容易做到的。為了測試晶片，本篇設計了連續近似類比數轉換器，它的取樣頻率是51.2 kS/s，解析度是9碼，ENOB為7.8。
此晶片將植入病人體內，因此其完整測試非常重要，但測試所有的可能性非常花時間，可以說是近乎不可能，所以減少測試數量是很重要的，而且過長的測試時間對於商業考量來說是一大成本，本篇認為在人眼無法分辨的基礎下，測試影像可以被簡化成16個亮度層級以減少測試時間且提升測試效率。此外，還研究分析了晶片系統性變異及局部性變異對輸出影像的影響，希望結果在未來可以用以幫助減少不必要的測試圖案；最後提出了PSNR於非線性誤差模擬及局部性變異模擬的快速算法，以減少大量的模擬時間。

The number of patients suffering from retinal diseases such as Age-related macular degeneration (AMD) and retinitis pigmentosa (RP) are increasing every year in the world. Treatments by retina prosthesis for AMD and RP are fruitful in recent years. Retinal prosthesis is one of treatment and used to replace the function of the damaged cells.
A controller with a built-in clock is developed for the retinal prosthesis chip. All control signals in the chip are well maneged by the controller. The architecture of the controller is a flexible design. It is easy to modify the pulse width or any rising and falling timing whenever the specification is changed in design phase. A SAR ADC is designed for chip testing. The sample rate is 51.2 kS/s, the resolution is 9 bits and ENOB is 7.8 bits.
This chip will be implanted in human body so the complete testing is very crucial. However, testing all patterns takes very long time and is almost impossible. To reduce test patterns is important since long test time is a lot of cost for commercial consideration. The test images could be simplified to 16 light intensity levels which could reduce test pattern number and increase testing efficiency. Also, the influence of the output images from the retinal prosthesis chip with systematic variation and local variation is studied and analyzed. The results could help us reduce the unnecessary test patterns. The PSNR calculation in non-linearity error and local variation are proposed, which could save a lot of simulation time.

摘要………………………………………………………………………….……….………….…. ii
Abstract……………………………………………………………………………………………...iii
Table of Contents…………………………………………………………………………………... iv
List of Figures………………………………………………………………………………………vii
List of Tables………………………………………………………………………………………...xi
Chapter 1 Introduction……………………………………………………………..…………………1
1.1 Background…………………………….……….…………….…………………………….1
1.2 Motivation…………………………………………………………………………………..2
1.3 Retinal Prosthesis Chip……………………………………………………………………..3
1.4 Organization……………………………………….…….………………….………………6
Chapter 2 Controller…………………………….……………….…….….…………….……………7
2.1 Objective……………………………….…….…….……………………………………….7
2.2 Approach……………………………………………………………………………………9
2.3 Block Diagram……………………………………………………………………………..11
2.4 Circuits Implementation……………………………………………………………...……12
2.4.1 Clock Generator………………………………………………………….…………..12
2.4.2 Frequency Divider…………………………………………………………………...12
2.4.3 Pulse Generator…………………………………………………………..………….14
2.4.4 Window Generator…………………………………………………………………..16
2.4.5 Cluster Signal Generator…………………………………………………………….17
2.5 Layout and Measurement Results…………………………………………………………19
2.6 Summary………………………………………....………….....………....………......……23
Chapter 3 Successive Approximation Register Analog-to-Digital Converter ……………………...24
3.1 Principle and Architecture…………………………………..….………………………….24
3.2 Circuit Implementation…………………………………………………………………….26
3.2.1 Track and Hold Circuit with Bootstrapped Analog Switch………………….….….26
3.2.2 Comparator…………………………………………………………………………28
3.2.3 SAR Control Logic………………………………………………………………....28
3.3 Experimental Results………………………....….……....……......……..…......…….……29
Chapter 4 Image Comparison……………………………………….............……………...…….…32
4.1 Two Image Quality Indexes……………………………………………………………….32
4.2 Ten Sample Pictures……………………………………………………………………….34
4.3 SSIM Using Boundary Condition…………………………………………………....……36
4.3.1 Three Boundary Conditions………………………………………………….….…37
4.3.2 Non-linearity Systematic Variation Simulation.…….………….………….………39
4.3.3 Simulation Results………………………………………….………………………40
4.4 Reducing Number of Light Intensity Levels………………………………………………52
4.4.1 Number of Light Intensity Levels……………………………………….…………52
4.4.2 Results…………………………………….………….……………….……………53
4.5 Summary…………………………………………………………………………………...55
Chapter 5 Systematic Variation and Local Variation……………………………………..…...……56
5.1 Systematic Variation………………………………………………………………………56
5.1.1 Three Systematic Variation…………………………………………………...……56
5.1.2 Systematic Variation Simulation…………………………………………………...59
5.1.3 Results and Analysis………………………………………………………………..60
5.1.4 Summary……………………………………………………………………………86
5.2 Local Variation……………………………………………………………………….……86
5.2.1 Local Variation………………………………………………………………..……86
5.2.2 Local Variation Simulation……………………………………………….……..…87
5.2.3 Results and Analysis………………………………………………………..………88
5.2.4 Summary……………………………………………………………………………93
5.3 PSNR calculation…………………………………………………………………………..94
5.3.1 Non-linearity Error…………………………………………………………………94
5.3.2 Local Variation……………………………………………………………………..99
5.4 Summary………………………………………………………………………………….102
Chapter 6 Conclusions and Future Works…………………………………………………………103
6.1 Conclusions………………………………………………………………………………103
6.2 Future Works……………………………………………………………………………..104
References…………………………………………………………………………………………106

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