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4.3 M E M O R Y SPACE
The memory space o f the 68000 is divided into two major areas. T h e upper half of
memory is available for the user. This 8 Mbyte space has no breadboard circuitry or
memory located in it. T h e lower half of memory contains all of the breadboard's I/O
ports, the onboard memory and circuitry.
The address space is decoded as follows:
000000 - 1FFFFF
200000 - 3FFFFF R e s e r v e d
400000 - 5FFFFF
600000 - oFFFFF N o n - v o l
700000 - 71FFFF T i m e r
740000 - 77FFFF S e r i a l Interface
780000 - 7BFFFF
7C0000 - 7FFFFF
800000 - FFFFFF
A list of internal routines available to the user are provided in Appendix A.
4.3.1 E P R O M Organization
low memory #1-10
high memory
0 0 0 0 0
0 0 1 0 0
0 0 7 F F
0 0 8 0 0
OFFFF +
1FFFF +
R
O
M
R
A
M
I
/
O
ports on local bus
V
X
I
interface
U s e r
area
-
#H100
-
#H800
-
#H10000
EPROM M e m o r y M a p
l E x c e p t i o n V e c t o r s
Jump T a b l e
VT- 1 S y s t e m
F i r m w a r e
U s e r - A p p l i c a t i o n
Code
Vectors
Jump Table
Breadboard Code
-
User Code
4-3
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