K25C81-FB Semtech, K25C81-FB Datasheet - Page 6

• Manufacturer Part Number: K25C81-FB
• Description: Versatile PC/XC/AT/PS/2 Compatible Keyboard Encoder
• Manufacturer: Semtech

Copyright Semtech, 1997-2001
DOC5-C81-DS-105
SUGGESTED INTERFACING FOR K25C81-FN (44-PIN PLCC PACKAGE)
STANDARD KEYMAP FOR K25C81
EXTERNAL_KBD_PS2CLOCK
EXTERNAL_KBD_PS2DATA
HOST_PS2CLOCK
HOST_PS2DATA
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
0
F29
Pg Dn
]
v
o
h
a
.
S
J
A
1
f3
f14
f1
Ins
Back-quote
’(Apostrophe)
* Typematic Keys
1
F28
Home
(
w
p
i
b
, (comma)
T
K
B
2
f4
f13
Backspace
Esc
!
"
2x4.7K
C2
R1
VCC
R2
C3
R3
C4
R4
C5
n
n
2
End
PgUp
)
x
q
j
c
- (dash)
U
L
C
3
f6
f12
Rt Arrow*
Up Arrow*
@
<
Upper case A–Z correspond to Shift a–Shift z
F21–F30 correspond to Ctrl F1–Ctrl F10
2x2K
VCC
4x47pF
6
1
U1
TC54VC4502ECB
TELCOM
VCC
PBRC4.00BR
4.00MHz
11
10
41
23
9
8
3
2
4
7
AVX
Y1
EKD
EKC
EKC1
KC
KD
NC
NC
IRQ
VX
RP
R5
1M
3
F36
:
*
y
r
k
d
/
V
M
D
4
f5
f15
Dn Arrow*
Lft Arrow*
-
>
C1
.1uF
VCC
Rows (R0-R7)
K25C81-FN
PLCC
U2
+
10uF
C6
C17
C16
C15
C14
C13
C12
C11
C10
C4A
R7A
4
F34
F27
^
z
s
l
e
%
W
N
E
5
f7
f11
F38
R
{
?
C9
C8
C7
C6
C5
C4
C3
C2
C1
C0
R7
R6
R5
R4
R3
R2
R1
R0
5
12
24
25
26
27
28
29
30
31
21
20
19
17
16
15
14
13
18
40
39
6
37
36
35
34
33
32
RP1
NET_15K
VCC
VCC
5
F35
F30
F22
;
t
m
f
&
X
O
F
6
f8
f16
Space
Enter
}
~
www.semtech.com
100K
n
n
R6
F11–F20 correspond to Shift F1–Shift F10
F31–... correspond to Alt F1–Alt F10
JP1
(c)1994-2001 USAR SYSTEMS, Inc.
Application Circuit for K25C81-FB
Document Number
6
F33
F31
F21
[
u
n
g
#
Y
P
G
7
f9
9
F19
$
\
Tab
JUPERS SETTINGS
JP1
C17
C16
C15
C14
C13
C12
C11
C10
C9
C8
C7
C6
C5
C4
C3
C2
C1
C0
K25C81FB.sch
R7
R6
R5
R4
R3
R2
R1
R0
1-2:
2-3
Rev
.6
PC/XT
PC/AT
7
F37
F32
F25
F20
F23
F18
i
0
Z
Q
H
8
f2
f10
+
=
|
Del