Bally 5000 Plus, Manual

Page: 62 / 388

68000 M i c roprocessor
The 68000 m i c rop rocessor I s a 1 6
b i t m i cr o-processor wh i ch h a s an
async h r onous bus s t r u c t u r e . I t
uses 1 6 con t r o l s i gna l s . The 2 3
b i t add ress bus a n d a 1 6 b i t da t a
bus a l l ow t he t r an s f e r o f da t a
I n
b y t es or wor ds . The 68000 h a s mor e
capab l I I t l es and ope r a t e s f a s t e r
t h an an 8 b i t 6800 w i t h a
synchronous bus s t r u c t ur e .
Howeve r , t he 68000 can suppor t 6800
ch i ps ( dev i ces ) . The m i cr op r ocessor
ope r a t e s at 8 MHz .
6800 c h i p ( dev i ce )
Any 8 b i t dev i ce w i t h synchronous
bus con t ro l of da t a f l ow . The
fo l l ow i ng s i gna l s a r e un i que to
t h i s c h i p .
E enab l e
VPA va l i d per i ph e r a l address
VMA v a l i d memo r y address
68000 ch i p ( dev i ce )
Any 8 b i t dev i ce w i t h async h r onous
bus con t r o l of da t a f l ow . The
fo l l ow i ng s i gn a l s are un i que to
t h i s ch i p .
AS
address s t robe
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uppe r da t a s t robe
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A D D R E S S
B U S
S Y S T E M
C O N T R O L
NOTE S
3 .
MPU
BOARD
68 H C OO O P- 8
A 23
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A22
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A 2 1
' 8
A 20
A
19
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40 A I2
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38 Ala
37 A9
36 .8
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34 A6
33 .�
32
3 1
& 3
30
A 2
29
' 1
'9
vee
vee
16 GJrIIO
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G N O
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ClO
18
" E S E T
17 -
HALT
U l
2 1
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09 60
6 1
0 8
0 7 62
06 63
O� 6'
O.
03
02
0 1
0 0 �
DATA B U S
A S Y N C H R O N O U S
+
SY N C H R O N O U S
28
F e o
I N T E R R U P T
C O N T R O L
P R O C E S S O R
S T A T U S
Fe2
8 "
B G ACK
9G
1 3
IZ
1 1
20
ASY N C H R O N OU S
S Y N C H R O N O U S
F i g . 3-1
3-5