K25C81-FB Datasheet, PDF (6/12 Pages) Semtech Corporation – Versatile PC/XC/AT/PS/2 Compatible Keyboard Encoder

SUGGESTED INTERFACING FOR K25C81-FN (44-PIN PLCC PACKAGE)
EXTERNAL_KBD_PS2DATA
EXTERNAL_KBD_PS2CLOCK
HOST_PS2DATA
HOST_PS2CLOCK
VCC
VCC
U1
1
TC54VC4502ECB
TELCOM
VCC
C1
.1uF
R1 R2 R3 R4
2x4.7K
2x2K
+ _C6
10uF
C2 C3 C4 C5
4x47pF
11 _EKD
10 _EKC
41 _EKC1
9 _KC
8 _KD
VCC
3
23
NC
NC
2 _IRQ
4 _VX
7 _RP
U2
K25C81-FN
PLCC
C17
C16
C15
C14
C13
C12
5
12
24
25
26
27
C11
C10
C9
C8
C7
C6
C5
C4
C3
C2
C1
C0
28
29
30
31
21
20
19
17
16
15
14
13
C4A ¹⁸
R7A
R7
R6
R5
R4
R3
R2
R1
R0
40
39
6
37
36
35
34
33
32
R5
1M
VCC
R6
100K
VCC
RP1
NET_15K
Y1
4.00MHz
AVX
PBRC4.00BR
JUPERS SETTINGS
JP1
JP1
1-2: PC/XT
2-3 PC/AT
C17
C16
C15
C14
C13
C12
C11
C10
C9
C8
C7
C6
C5
C4
C3
C2
C1
C0
R7
R6
R5
R4
R3
R2
R1
R0
(c)1994-2001 USAR SYSTEMS, Inc.
Application Circuit for K25C81-FB
Document Number K25C81FB.sch ^{Rev .6}
STANDARD KEYMAP FOR K25C81
0
1
0 ^F29
1 Pg Dn
F28
Home
2]
(
3v
w
4o
5h
6a
7.
8S
9J
10 _A
11 ₁
12 _f3
13 _f14
14
15
f1
16 ^Ins
17 ^Back-quote
’(Apostrophe)
p
i
b
, (comma)
T
K
B
2
f4
f13
Backspace
Esc
!
"
* Typematic Keys
Rows (R0-R7)
2
3
4
End
F36
F34
PgUp
:
F27
)
*
^
x
y
z
q
r
s
j
k
l
c
d
e
- (dash)
/
%
U
V
W
L
M
N
C
D
E
3
4
5
f6
f5
f7
f12
f15
f11
Rt Arrow*
Dn Arrow*
F38
Up Arrow*
Lft Arrow*
R
@
-
{
<
>
?
n Upper case A–Z correspond to Shift a–Shift z
n F21–F30 correspond to Ctrl F1–Ctrl F10
5
6
7
F35
F33
F37
F30
F31
F32
F22
F21
F25
;
[
F20
t
u
F23
m
n
F18
f
g
i
&
#
0
X
Y
Z
O
P
Q
F
G
H
6
7
8
f8
f9
f2
f16
9
f10
Space
F19
+
Enter
$
=
}
\
|
~
Tab
Del
n F11–F20 correspond to Shift F1–Shift F10
n F31–... correspond to Alt F1–Alt F10
Copyright Semtech, 1997-2001
6
DOC5-C81-DS-105
www.semtech.com