A
ll
and more about Sharp PC-1500
at
http://
www
.PC-1500.info
2-2-4. CPU pin description
~
:::~
~
= e
C O t--. l
MN
-
U
OOO
OOO~c~z
o88
3ooo8
Z<<<<<<<><C<<<<<<<<
R/ l'I
~-E~~ ~~~
G
G47•e«CG
4
1
~B
~
.
07
p4,
59
37
06
PV
60
36
05
PU
61
3S
04
4,
os
62
34
03
XLO
63
33
02
X
LI
64
32 01
V'°AI
T
65
31
DO
I
N7
66
LH
5801
30
MEO
I
NG
67
29
M
EI
INS
68
(T
OP
VIEW)
28
OD
I
N4
69
27
HO
IN3
70
26 Hl
IN2
71
25
H2
INl
72
24
H3
1
1\'I)
73
23
H4
NC
74
22
HS
NC
75
21
H6
NC
76
20
H7
1 2 3 4 s 6 7 8 9 1
01
11213
14
15 1617 18 19
....
w
(/)
o
oou..
:s::u c ~ -
w O
m~o~&cuo~OC~~
-
1
~cm
~z
mm>
m
om>>>>>>Z~zzo
0
XLO
,
XL1
The
se
ar
c external Cr
)'S
tal
co
rmcc1
io
n pins. X
1.0
is the i
nput
pin
and
XLI
is the o
utput
pin. Clock frequency is div
id
ed
by t
wo
inside the C PU.
Wh
en
the
2.6M H
7.
cr
ys
tal is
c
onnecttd.
the CP U
o
~ra1
es
1111d
cr
I .3M Hz
of
internal machine cycle.
(j)
ADO
- AD15
A
ddr
e
ss
bus. Ou
tput
s from th
ese
pins arc 3-srnte (three om p
ut
states of high. l
ow
and
high impe
da
nce)
and
go
h
ig
h
imp
eda
nce with
BR
Q (Bus Rc
Qu
cst). Bas ica
ll
y.
MK
bytes
of
1nc
rn
ory
area
i
:s
~uppo
r
t
c
d
r(>r
dir
ec
t
ac
cc~
:sin
g,
hut it is n
la
dc po
ssi
b
le
to
acc
ess
even
I 28K
area
of
memory
ar
ea wh
en
MEO
a nd
ME
I
ar
e used.
(i)
00
-
07
l~
idi
rec
tiona
l
da
ta
bu
s \Vhich i:s used co 'vrite
or
data
to
/ f
ront
the exte
rnal
n1
cn
1ory.
©MEO,
ME1
Mc
rn
o.-y enable signals. As m
emor
y
ar
ea of 64K bytes is accessed by M
EO
and
anot
h
er
64K
by
tes by M EI. it permits
dir
ect
acc
es
s
of
m
emory
area
of
128K
bytes in t
ota
l.
Since
f\1
EO is us
ed
fol' instru
ct
i
on
fet
ch
an
d s
tack
opera
tion. acce
ss
in
g by
n1cans
o.
fthc
progr
a1l1
C<
ltirtter J
">
an
d stack p
<>i
nter S is lin1itcd t
<>
a n)axinttHtl
of
64K bytes.
As for darn accessing.
bo
th m
emo
ry
area
s
co
vered by M EOand M
El
can
be
co
ntrolled
by a
CPU
i
ns
tru
cti
on
.
9
Do
not sale this
PDF!!!
To Next Page
