viii
M68000 USER’S MANUAL
MOTOROLA
TABLE OF CONTENTS (Continued)
Paragraph
Number
Page
Number
Title
Section 4
8-Bit Bus Operations
4.1
4.1.1
4.1.2
4.1.3
4.2
Data Transfer Operations.............................................................................
Read Operations ......................................................................................
Write Cycle ...............................................................................................
Read-Modify-Write Cycle..........................................................................
Other Bus Operations...............................................................................
4-1
4-1
4-3
4-5
4-8
Section 5
16-Bit Bus Operations
5.1
5.1.1
5.1.2
5.1.3
5.1.4
5.2
5.2.1
5.2.2
5.2.3
5.3
5.4
5.4.1
5.4.2
5.4.3
5.4.4
5.5
5.6
5.7
5.8
Data Transfer Operations............................................................................
Read Operations .....................................................................................
Write Cycle ..............................................................................................
Read-Modify-Write Cycle.........................................................................
CPU Space Cycle....................................................................................
Bus Arbitration ..........................................................................................
Requesting The Bus..............................................................................
Receiving The Bus Grant ......................................................................
Acknowledgment of Mastership (3-Wire Arbitration Only).....................
Bus Arbitration Control..............................................................................
Bus Error and Halt Operation....................................................................
Bus Error Operation ..............................................................................
Retrying The Bus Cycle.........................................................................
Halt Operation .......................................................................................
Double Bus Fault...................................................................................
Reset Operation........................................................................................
The Relationship of
DTACK, BERR
, and
HALT
.........................................
Asynchronous Operation ..........................................................................
Synchronous Operation ............................................................................
5-1
5-1
5-4
5-7
5-9
5-11
5-14
5-15
5-15
5-15
5-23
5-24
5-26
5-27
5-28
5-29
5-30
5-32
5-35
Section 6
Exception Processing
6.1
6.1.1
6.1.2
6.1.3
6.1.4
6.2
6.2.1
6.2.2
6.2.3
Privilege Modes............................................................................................
Supervisor Mode ......................................................................................
User Mode................................................................................................
Privilege Mode Changes ..........................................................................
Reference Classification...........................................................................
Exception Processing...................................................................................
Exception Vectors ....................................................................................
Kinds Of Exceptions.................................................................................
Multiple Exceptions...................................................................................
6-1
6-2
6-2
6-2
6-3
6-4
6-4
6-5
6-8