Images courtesy of Addison Wesley Longman, Inc. Copyright © 2001 Chapter 3 Instruction Set Architectures

Images courtesy of Addison Wesley Longman, Inc. Copyright © 2001 Images courtesy of Addison Wesley Longman, Inc. Copyright © 2001

Chapter 3Chapter 3Instruction Set ArchitecturesInstruction Set Architectures


Chapter OutlineChapter Outline

• Programming LanguagesProgramming Languages

• Assembly LanguagesAssembly Languages

• Instruction Set Architecture DesignInstruction Set Architecture Design

• A Relatively Simple ISAA Relatively Simple ISA

• ISA of the 8085 microprocessorISA of the 8085 microprocessor


Programming LanguagesProgramming Languages

• High level languagesHigh level languages

• Assembly languagesAssembly languages

• Machine languagesMachine languages


Compilation ProcessCompilation Process


Assembly ProcessAssembly Process


Java AppletsJava Applets


Assembly Language AttributesAssembly Language Attributes

• Instruction typesInstruction types

• Data typesData types

• Addressing modesAddressing modes

• Instruction formatsInstruction formats


Instruction TypesInstruction Types

• Data transferData transfer

• Data operationData operation

• Program controlProgram control


Data TypesData Types

• Numeric (integer, floating point)Numeric (integer, floating point)

• Boolean (true, false)Boolean (true, false)

• Character (ASCII, Unicode)Character (ASCII, Unicode)


Addressing modes - DirectAddressing modes - Direct


Addressing modes - IndirectAddressing modes - Indirect


Addressing modes - Register Addressing modes - Register DirectDirect


Addressing modes - Register Addressing modes - Register IndirectIndirect

@ R


Addressing modes - Addressing modes - ImmediateImmediate


Addressing modes - ImplicitAddressing modes - Implicit


Addressing modes - RelativeAddressing modes - Relative


Addressing modes - IndexedAddressing modes - Indexed


Instruction FormatsInstruction Formats

• More operands = less instructionsMore operands = less instructions

• More operands = larger wordsMore operands = larger words


3-operand Instructions3-operand Instructions








Instruction Set ArchitectureInstruction Set Architecture

• Instruction setInstruction set

• Register setRegister set

• Memory access informationMemory access information


ISA AttributesISA Attributes

• CompletenessCompleteness

• OrthogonalityOrthogonality

• Register set designRegister set design


ISA RequirementsISA Requirements

• Backward compatibility?Backward compatibility?

• Data types/sizesData types/sizes

• Interrupts?Interrupts?

• Conditional instructions?Conditional instructions?


A Relatively Simple ISA - A Relatively Simple ISA - RegistersRegisters

• Accumulator Accumulator ACAC

• General purpose register General purpose register RR

• Flag Flag ZZ


A Relatively Simple ISA - A Relatively Simple ISA - Instruction SetInstruction Set


A Relatively Simple ISA - A Relatively Simple ISA - Instruction Set (continued)Instruction Set (continued)


A Relatively Simple ISA - A Relatively Simple ISA - Instruction FormatsInstruction Formats


Example Relatively Simple Example Relatively Simple ProgramProgram

1

1 2 ... , or

This could be written as a high-level language

code snippet as follows.

total=0;

FOR i=1 to n DO {total = total + i};

1. total = 0, i = 0

2. i =

n

i

n i

i + 1

3. total = total + i

4. IF i n THEN GOTO 2


Example Relatively Simple Example Relatively Simple Program CodeProgram Code


Example Relatively Simple Example Relatively Simple Program TraceProgram Trace


A Relatively Simple ISA - A Relatively Simple ISA - AnalysisAnalysis





The 8085 ISA - RegistersThe 8085 ISA - Registers

• Accumulator Accumulator AA

• General purpose registers General purpose registers BB, , CC, , DD, , EE, , HH, , LL

• Stack pointer Stack pointer SPSP

• Flags Flags SS, , ZZ, , PP, , CYCY, , ACAC


The 8085 ISA - Instruction SetThe 8085 ISA - Instruction Set• Data movement instructionsData movement instructions


The 8085 ISA - Instruction SetThe 8085 ISA - Instruction Set• Data operation instructionsData operation instructions


The 8085 ISA - Instruction SetThe 8085 ISA - Instruction Set• Program control instructionsProgram control instructions


The 8085 ISA - Instruction The 8085 ISA - Instruction FormatsFormats


Example 8085 ProgramExample 8085 Program

1

1 2 ... , or

1. i = n, sum = 0

2. sum = sum + i, i = i - 1

3. IF i 0 THEN GOTO 2

4. total = sum

n

i

n i


Example 8085 Program CodeExample 8085 Program Code


Example 8085 Program TraceExample 8085 Program Trace


The 8085 ISA - AnalysisThe 8085 ISA - Analysis





SummarySummary

• Programming LanguagesProgramming Languages

• ISA DesignISA Design

Documents

Images courtesy of Addison Wesley Longman, Inc. Copyright © 2001 Chapter 3 Instruction Set Architectures