Contents

Page

1

Introduction

1

1.1

Brief History of computing

2

1.2

Technological Developments

3

1.3

FPGA Technology

4

1.4

Choice of Processor

4

2

Processor Details

6

2.1

Processor Overview

7

2.2

Processor Specification

8

2.3

Basic Instruction Set

10

2.4

Microcoded Instructions

12

3

Implementation Method

14

3.1

Data path Changes

15

3.2

State Model

16

3.3

Data path Complexity

16

3.4

Implementation Choices

17

3.5

Registers

18

3.6

Removed Items

18

3.7

State Model Refinement

19

3.8

Initial Data Path

21

3.9

Program Counter

24

3.10

Output Requirements

25

3.11

Final State Diagram

25

3.12

Variable Execution Time

26

3.13

Microcoded Instruction Mapping

27

3.14

Final Data Path

28

3.15

Signal to State Assignment

29

3.16

VHDL Coding

30

3.17

VHDL to Gates

33

3.18

Xilinx Generation

33

4

Testing

34

4.1

Testing Strategy

35

4.2

First Test Program

36

4.3

Detailed Testing

38

4.4

Xilinx Testing

38

4.5

Performance Increase, Power Decrease

40

5

Conclusion

41

5.1

42

6

Bibliography

44

7

Appendix

46