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FlexiCoderTM K25C81 Versatile PC/XC/AT/PS/2 Compatible Keyboard Encoder
HID & SYSTEM MANAGEMENT PRODUCTS, KEYCODERTM FAMILY DESCRIPTION The FlexiCoder is a versatile, lowpower 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.
TM
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 autorepeat for designated keys • Offers two-key inhibit scanning mode
On an 8 x 18 matrix, the FlexiCoderTM 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 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.
TM
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
FlexiCoderTM 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
ORDERING CODE
Package options 40-pin, Plastic DIP 44-pin, Plastic PL.