
S
c
h
e
m
a
t
i
c
D
i
a
g
r
a
m
s
4
-
1
2
C
P
L
D
D
e
v
e
l
o
p
m
e
n
t
/
P
r
o
g
r
a
m
m
e
r
K
i
t
U
s
e
r
G
u
i
d
e
3
3
0
0
A
–
P
L
D
–
0
8
/
0
2
F
i
g
u
r
e
4
-
1
1
.
S
c
h
e
m
a
t
i
c
D
i
a
g
r
a
m
o
f
A
t
m
e
l
C
P
L
D
I
S
P
C
a
b
l
e
,
C
o
n
t
i
n
u
e
d
R15
30K
R11
4.7K
R3 100
R13
4.7K
R14
3.3K
R10
4.7K
D4
1N4148
R4 100
D3
1N4148
D2
1N4148
R2 100
R7
100
R6
100
13
25
12
24
11
23
10
22
9
21
8
20
7
19
6
18
5
17
4
16
3
15
2
14
1
P1
DB25
-
+
5
6
7
8
4
U2B
LM393
R8
100
R5
100
R9
100
-
+
3
2
1
8
4
U2A
LM393
R12
10K
STROBE
AUTO
INIT
SEL_IN
ERROR
D0
ERROR
D7
BUSY
nACK
GND
VCC
GND
VCC
GND
VCC
VCC
Parallel Port Section
Vref
1.5V - 1.6V
Voltage Detection
8-SOP
8-SOP
3V = 0
5V = 1
1.36V at VCC = 3.3
2.06V at VCC = 5.0