K25C81-P
| Model | K25C81-P |
| Description | Versatile PC/XC/AT/PS/2 Compatible Keyboard Encoder |
| PDF file | Total 12 pages (File size: 127K) |
| Chip Manufacturer | SEMTECH |
FlexiCoder
TM
K25C81
Versatile PC/XC/AT/PS/2 Compatible
Keyboard Encoder
HID & SYSTEM MANAGEMENT PRODUCTS, KEYCODER
TM
FAMILY
DESCRIPTION
The FlexiCoder
TM
is a versatile, low-
power keyboard encoder. It offers
two bi-directional channels for
communicating with a
PC/XT/AT/PS2 system, and/or any
optional keyboard-compatible
devices, such as an 83 or 101/102
standard desktop keyboard, OCR,
barcode reader, etc. The K25C81
directly interfaces a PC keyboard
port, making custom keyboard to
system communications fully
transparent.
On an 8 x 18 matrix, the
FlexiCoder
TM
will scan, debounce
and encode up to 144 keys. Scan
codes corresponding to single keys
of the IBM 101 keyboard, or a
combination of these keys when
depressed with Shift, Ctrl, and Alt
keys, are generated with each key
press. Custom keypad input is not
effected by the Shift States of an
external keyboard.
Users can conveniently define key
assignments on the matrix as single
or repeating actions. All keys must
be released between key strokes or
scanning is suspended. The
encoder can buffer up to 122
keycodes, and control inputs and
outputs are provided for interfacing
with contact keyboards.
The FlexiCoder
TM
is ideal for use
with either BIOS-compatible chip
sets or single-board computers for
PC systems requiring a custom
keyboard / keypad as an alternate
or additional input device. Boards
and evaluation kits are immediately
obtainable and ready to connect.
FEATURES
• Directly interfaces a PC
keyboard port
• Encodes up to 144 custom keys
on an 8 X 18 matrix
• Buffers up to 122 keycodes
• Interfaces to 83/101/102
standard keyboard or other
8042-compatible device
APPLICATIONS
•
•
•
•
•
Custom keyboards/keypads
Control panels
Automatic teller machines
Embedded control systems
Public Information Kiosks
•
•
•
•
•
Instrumentation
Test and Measurement equipment
Point of Sales terminals
Industrial Controllers
Medical Instruments
• Enables custom keypad scan
codes to remain unaffected by
the Shift States of an external
keyboard
• Includes jumper-selectable auto-
repeat for designated keys
• Offers two-key inhibit scanning
mode
PIN ASSIGNMENTS
_RESET
_IRQ
VX
C17
R6
RP
KD
KC
EKC
EKD
C16
C0
C1
C2
C3
C4
C5
C6
C7
Vss
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
40 Vcc
39 OSCI
38 OSCO
R6
C17
VX
NC
_IRQ
_RESET
VCC
OSCI
OSC0
EKC1
NC
36 R7
35 NC
34 R5
33 R4
32 R3
RP
KD
KC
EKC
EKD
C16
C0
C1
C2
C3
C4
7
6
1
40
39
1
R7
NC
R5
R4
R3
R2
R1
R0
C8
C9
C10
C17
VX
_IRQ
_RESET
NC
NC
VCC
OSCI
OSCO
EKC1
R7
37 EKC1
DIP
31 R2
30 R1
29 R0
28 C8
27 C9
26 C10
25 C11
24 C12
23 C13
22 C14
21 C15
12
PLCC
34
17
18
23
29
28
R6
RP
KD
KC
EKC
EKD
C16
C0
C1
C2
C3
QFP
NC
R5
R4
R3
R2
R1
R0
C8
C9
C10
C11
NC
C5
C6
C7
VSS
NC
C15
C14
C13
C12
C11
FlexiCoder
TM
is a trademark of Semtech Corp. All
other trademarks belong to their respective
companies.
Copyright Semtech, 1997-2001
DOC5-C81-DS-105
1
www.semtech.com
C4
C5
C6
C7
NC
VSS
C15
C14
C13
C12
NC
