Section 1 Introduction
1.1 Integer Unit User Programming Model . . . . . . 1-2
1.1.1 Data Registers (D7 – D0)? . . . . 1-2
1.1.2 Address Registers (A7 – A0)? . . 1-2
1.1.3 Program Counter?? . . 1-3
1.1.4 Condition Code Register? . . . . . 1-3
1.2 Floating-Point Unit User Programming Model? 1-4
1.2.1 Floating-Point Data Registers (FP7 – FP0)? . 1-4
1.2.2 Floating-Point Control Register (FPCR)? . . . 1-5
1.2.2.1 Exception Enable Byte . . . . . 1-5
1.2.2.2 Mode Control Byte . . . . . . . . 1-5
1.2.3 Floating-Point Status Register (FPSR)? . . . . 1-5
1.2.3.1 Floating-Point Condition Code Byte . . . . . 1-5
1.2.3.2 Quotient Byte? . . . 1-6
1.2.3.3 Exception Status Byte. . . . . . 1-6
1.2.3.4 Accrued Exception Byte . . . . 1-7
1.2.4 Floating-Point Instruction Address Register (FPIAR)? 1-8
1.3 Supervisor Programming Model . 1-8
1.3.1 Address Register 7 (A7)? . . . . 1-10
1.3.2 Status Register?? . . 1-10
1.3.3 Vector Base Register (VBR)? . 1-11
1.3.4 Alternate Function Code Registers (SFC and DFC)? 1-11
1.3.5 Acu Status Register (MC68EC030 only)? . . 1-11
1.3.6 Transparent Translation/access Control Registers? . 1-12
1.3.6.1 Transparent Translation/access Control Register Fields for the
M68030? . . . 1-12
1.3.6.2 Transparent Translation/access Control Register Fields for the
M68040? . . . 1-13
1.4 Integer Data Formats? . . . . . . . . 1-14
1.5 Floating-Point Data Formats? . . 1-15
1.5.1 Packed Decimal Real Format? 1-15
1.5.2 Binary Floating-Point Formats? 1-16
1.6 Floating-Point Data Types? . . . . 1-17
1.6.1 Normalized Numbers . . . . . . . 1-18
1.6.2 Denormalized Numbers . . . . . 1-18
1.6.3 Zeros?? . . . . . . 1-19
1.6.4 Infinities?? . . . . 1-19
1.6.5 Not-A-Numbers?? . . 1-19
1.6.6 Data Format and Type Summary? . . . . . . . 1-20
1.7 Organization of Data in Registers? . . . . . . . . 1-25
1.7.1 Organization of Integer Data Formats in Registers? . 1-25
1.7.2 Organization of Integer Data Formats in Memory? . . 1-27
1.7.3 Organization of Fpu Data Formats in Registers and Memory . . . . . . 1-30
Section 2 Addressing Capabilities
2.1 Instruction Format?? . . 2-1
2.2 Effective Addressing Modes . . . . 2-4
2.2.1 Data Register Direct Mode? . . . 2-5
2.2.2 Address Register Direct Mode . 2-5
2.2.3 Address Register Indirect Mode?? 2-5
2.2.4 Address Register Indirect with Postincrement Mode . 2-6
2.2.5 Address Register Indirect with Predecrement Mode? . 2-7
2.2.6 Address Register Indirect with Displacement Mode? . 2-8
2.2.7 Address Register Indirect with Index (8-Bit Displacement) Mode . . . . 2-9
2.2.8 Address Register Indirect with Index (Base Displacement) Mode. . . 2-10
2.2.9 Memory Indirect Postindexed Mode? . . . . . 2-11
2.2.10 Memory Indirect Preindexed Mode? . . . . . . 2-12
2.2.11 Program Counter Indirect with Displacement Mode? 2-13
2.2.12 Program Counter Indirect with Index (8-Bit Displacement) Mode . . . 2-14
2.2.13 Program Counter Indirect with Index (Base Displacement) Mode. . . 2-15
2.2.14 Program Counter Memory Indirect Postindexed Mode? . . 2-16
2.2.15 Program Counter Memory Indirect Preindexed Mode? . . . 2-17
2.2.16 Absolute Short Addressing Mode? . . . . . . . 2-18
2.2.17 Absolute Long Addressing Mode . . . . . . . . 2-18
2.2.18 Immediate Data?? . . 2-19
2.3 Effective Addressing Mode Summary? . . . . . 2-19
2.4 Brief Extension Word Format Compatibility? . 2-21
2.5 Full Extension Addressing Modes? . . . . . . . . 2-22
2.5.1 No Memory Indirect Action Mode? . . . . . . . 2-24
2.5.2 Memory Indirect Modes? . . . . . 2-25
2.5.2.1 Memory Indirect with Preindex . . . . . . . . 2-25
2.5.2.2 Memory Indirect with Postindex . . . . . . . 2-26
2.5.2.3 Memory Indirect with Index Suppressed. 2-27
2.6 Other Data Structures? . . . . . . . 2-28
2.6.1 System Stack? 2-28
2.6.2 Queues?? . . . . 2-29
Section 3 Instruction Set Summary
3.1 Instruction Summary?? 3-1
3.1.1 Data Movement Instructions? . . 3-5
3.1.2 Integer Arithmetic Instructions? . 3-6
3.1.3 Logical Instructions?? 3-8
3.1.4 Shift and Rotate Instructions? . . 3-8

3.1.5 Bit Manipulation Instructions? . 3-10
3.1.6 Bit Field Instructions? . . . . . . . 3-10
3.1.7 Binary-Coded Decimal Instructions? . . . . . . 3-11
3.1.8 Program Control Instructions . 3-11
3.1.9 System Control Instructions . . 3-12
3.1.10 Cache Control Instructions (MC68040)? . . . 3-14
3.1.11 Multiprocessor Instructions? . . 3-14
3.1.12 Memory Management Unit (MMU) Instructions . . . . 3-15
3.1.13 Floating-Point Arithmetic Instructions? . . . . 3-15
3.2 Integer Unit Condition Code Computation? . . 3-17
3.3 Instruction Examples? . . . . . . . . 3-20
3.3.1 Using the Cas and Cas2 Instructions? . . . . 3-20
3.3.2 Using the Moves Instruction? . 3-20
3.3.3 Nested Subroutine Calls? . . . . 3-20
3.3.4 Bit Field Instructions? . . . . . . . 3-20
3.3.5 Pipeline Synchronization with the Nop Instruction . . 3-21
3.4 Floating-Point Instruction Details?? 3-21
3.5 Floating-Point Computational Accuracy? . . . . 3-23
3.5.1 Intermediate Result? . . . . . . . . 3-24
3.5.2 Rounding the Result? . . . . . . . 3-25
3.6 Floating-Point Postprocessing? . 3-27
3.6.1 Underflow, Round, Overflow? . 3-28
3.6.2 Conditional Testing? . . . . . . . . 3-28
3.7 Instruction Descriptions? . . . . . . 3-32
Section 4 Integer Instructions
Section 5 Floating Point Instructions
Section 6 Supervisor (Privileged) Instructions
Section 7 CPU32 Instructions
Section 8 Instruction Format Summary
8.1 Instruction Format
8.1 Instruction Format?? . . 8-1
8.1.1 Coprocessor ID Field . . . . . . . . 8-1
8.1.2 Effective Address Field? . . . . . . 8-1
8.1.3 Register/Memory Field? . . . . . . 8-1
8.1.4 Source Specifier Field? . . . . . . . 8-1
8.1.5 Destination Register Field? . . . . 8-2
8.1.6 Conditional Predicate Field? . . . 8-2
8.1.7 Shift and Rotate Instructions? . . 8-2
8.1.7.1 Count Register Field . . . . . . . 8-2
8.1.7.2 Register Field? . . . 8-2
8.1.8 Size Field? . . . . 8-4
8.1.9 Opmode Field?? 8-4
8.1.10 Address/Data Field?? 8-4
8.2 Operation Code Map?? 8-4
Appendix A
Processor Instruction Summary
A.1 MC68000, MC68008, MC68010 Processors? A-12
A.1.1 M68000, MC68008, and MC68010 Instruction Set? . A-12
A.1.2 MC68000, MC68008, and MC68010 Addressing Modes? A-16
A.2 MC68020 Processors . . . . . . . . A-17
A.2.1 MC68020 Instruction Set? . . . . A-17
A.2.2 MC68020 Addressing Modes? A-20
A.3 MC68030 Processors . . . . . . . . A-21
A.3.1 MC68030 Instruction Set? . . . . A-21
A.3.2 MC68030 Addressing Modes? A-24
A.4 MC68040 Processors . . . . . . . . A-25
A.4.1 MC68040 Instruction Set? . . . . A-25
A.4.2 MC68040 Addressing Modes? A-29
A.5 MC68881/MC68882 Coprocessors? . . . . . . . A-30
A.5.1 MC68881/MC68882 Instruction Set? . . . . . A-30
A.5.2 MC68881/MC68882 Addressing Modes? . . A-31
A.6 MC68851 Coprocessors . . . . . . A-31
A.6.1 MC68851 Instruction Set? . . . . A-31
A.6.2 MC68851 Addressing Modes? A-31
Appendix B Exception Processing Reference
B.1 Exception Vector Assignments for the M68000 Family? B-1
B.2 Exception Stack Frames? . . . . . . B-3
B.3 Floating-Point Stack Frames? . . B-10
Appendix C S-Record Output Format
C.1 S-Record Content? . . . C-1
C.2 S-Record Types?? C-2
C.3 S-Record Creation?? . . C-3