UR5HC418 Datasheet, PDF (1/14 Pages) Semtech Corporation – AT / PS/2 - Compatible Keyboard Encoder

DeskCoder^TM UR5HC418
AT / PS/2 - Compatible
Keyboard Encoder
HID & SYSTEM MANAGEMENT PRODUCTS, KEYCODER^TM FAMILY
DESCRIPTION
The DeskCoder^TM keyboard encoder
functions as a versatile, low-power
desktop keyboard encoder, while
providing two bi-directional
channels for communication with a
BIOS-compatible system as well as
any optional keyboard-compatible
devices, such as a 101/102/104
desktop keyboard, OCR, barcode
reader, etc.
The DeskCoder^TM fully supports the
IBM standard keyboard communi-
cation protocol; each key press
generates one of the scan codes
designated in the IBM Technical
Reference Manuals. The keyboard
encoder handles the scanning,
debounce, and encoding of 128
keys organized on an 8 x 16 matrix.
In addition to the system’s keyboard
communication port, the UR5HC418
provides a fully functional keyboard
input port that can be used by a
standard 101/102/104 keyboard or
another 8042-compatible device,
such as an external numeric
keypad, an OCR, or a bar-code
reader. Input from both the matrix
and the external device is
multiplexed and presented to the
system as if it were coming from a
single source.
The DeskCoder^TM is ideal for use in
low-power, low-cost and high-
reliability AT / PS/2 - compatible
keyboard designs.
Note: A version of the IC that
supports the PC/XT protocol is also
available. Contact Semtech for
more information.
FEATURES
• Interfaces contact switch matrix
keyboards to a BIOS-compatible
system
• Single IC desktop keyboard
encoder
• Provides interface for an external
keyboard/keypad or other 8042-
compatible devices
• AT / PS/2 - compatible
APPLICATIONS
• Desktop computers
• Instrumentation
• Industrial keyboards
PIN ASSIGNMENTS
• Implements all functions of a
101/102/104 keyboard
• Low-power HCMOS
microcontroller, suitable for 3-volt
battery-operated systems
• Available in DIP, PLCC and QFP
packages
• Custom versions available in small
or large quantities
• Point of sales terminals
• Public information kiosks
_RESET 1
40 VCC
_IRQ 2
39 OSCI
VX 3
38 OSCO
NL 4
37 EKC1
R6 5
36 R7
RP 6
35 SL
KD 7
34 R5
KC 8
33 R4
EKC 9
32 R3
EKD 10 _DIP 31 R2
CL 11
30 R1
C0 12
29 R0
C1 13
28 C8
C2 14
27 C9
C3 15
26 C10
C4 16
25 C11
C5 17
24 C12
C6 18
23 C13
C7 19
22 C14
VSS/GND 20
21 C15
RP
KD
KC
EKC
EKD
CL
C0
C1
C2
C3
C4
6
7
12
17
18
R6
1
RP
KD
KC
EKC
EKD
CL
C0
C1
C2
C3
1
PLCC
23
QFP
40
39 R7
SL
R5
R4
R3
34 R2
R1
R0
C8
C9
29 C10
28
NL
R5
R4
R3
R2
R1
R0
C8
C9
C10
C11
DeskCoder and KeyCoder are trademarks of
Semtech Corporation. All other trademarks
belong to their respective companies.
Copyright ©1997-2001 Semtech Corporation
1
DOC5-418-DS-109
www.semtech.com