MOTOROLA
M68040 USER’S MANUAL
xi
TABLE OF CONTENTS (Continued)
Paragraph
Page
Number
Title
Number
7.8.2.3
M68040 Synchronous DMA Arbitration ..........................................7-55
7.8.2.4
M68040 Asynchronous DMA Arbitration ........................................7-57
7.9
Bus Snooping Operation .......................................................................7-59
7.9.1
Snoop-Inhibited Cycle........................................................................7-60
7.9.2
Snoop-Enabled Cycle (No Intervention Required) ............................ 7-61
7.9.3
Snoop Read Cycle (Intervention Required) .......................................7-63
7.9.4
Snoop Write Cycle (Intervention Required) .......................................7-63
7.10
Reset Operation ....................................................................................7-65
7.11
Special Modes of Operation ..................................................................7-68
7.11.1
Output Buffer Impedance Selection ...................................................7-68
7.11.2
Multiplexed Bus Mode ....................................................................... 7-68
7.11.3
Data Latch Enable Mode ................................................................... 7-69
Section 8
Exception Processing
8.1
Exception Processing Overview ............................................................8-1
8.2
Integer Unit Exceptions ......................................................................... 8-5
8.2.1
Access Fault Exception ..................................................................... 8-6
8.2.2
Address Error Exception.................................................................... 8-8
8.2.3
Instruction Trap Exception .................................................................8-8
8.2.4
Illegal Instruction and Unimplemented Instruction Exceptions .......... 8-9
8.2.5
Privilege Violation Exception ............................................................. 8-9
8.2.6
Trace Exception .................................................................................8-10
8.2.7
Format Error Exception .....................................................................8-11
8.2.8
Breakpoint Instruction Exception ....................................................... 8-12
8.2.9
Interrupt Exception ............................................................................8-12
8.2.10
Reset Exception.................................................................................8-17
8.3
Exception Priorities ...............................................................................8-19
8.4
Return From Exceptions........................................................................8-20
8.4.1
Four-Word Stack Frame (Format $0) ................................................8-21
8.4.2
Four-Word Throwaway Stack Frame (Format $1) ............................. 8-21
8.4.3
Six-Word Stack Frame (Format $2) ...................................................8-22
8.4.4
Floating-Point Post-Instruction Stack Frame (Format $3) ................. 8-23
8.4.5
Eight-Word Stack Frame (Format $4)................................................8-23
8.4.6
Access Error Stack Frame (Format $7) .............................................8-24
8.4.6.1
Effective Address ...........................................................................8-24
8.4.6.2
Special Status Word (SSW) ...........................................................8-24
8.4.6.3
Write-Back Status .......................................................................... 8-26
8.4.6.4
Fault Address .................................................................................8-26
F
re
e
sc
a
le
S
e
m
ic
o
n
d
u
c
to
r,
I
Freescale Semiconductor, Inc.
For More Information On This Product,
Go to: www.freescale.com
n
c
..
.