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DeskCoderTM UR5HC418 AT / PS/2 - Compatible Keyboard Encoder
HID & SYSTEM MANAGEMENT PRODUCTS, KEYCODERTM FAMILY DESCRIPTION The DeskCoderTM 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 DeskCoderTM fully supports the IBM standard keyboard communication 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 DeskCoderTM is ideal for use in low-power, low-cost and highreliability 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 8042compatible devices • AT / PS/2 - compatible APPLICATIONS • Desktop computers • Instrumentation • Industrial keyboards PIN ASSIGNMENTS • Point of sales terminals • Public information kiosks • 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
6 RP KD KC EKC EKD CL C0 C1 C2 C3 C4 7 1
R6 NL VX VXA _IRQ _RESET VCC OSCI OSC0 EKC1 R7A 40 39
_RESET _IRQ VX NL R6 RP KD KC EKC EKD CL C0 C1 C2 C3 C4 C5 C6 C7 VSS/GND
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
40 39 38 37 36 35 34 33 32 31 30 29 28 27 26 25 24 23 22 21
VCC OSCI OSCO EKC1 R7 SL R5 R4 R3 R2 R1 R0 C8 C9 C10 C11 C12 C13 C14 C15
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PLCC
34
17 18
23
29 28
R7 SL R5 R4 R3 R2 R1 R0 C8 C9 C10
DIP
NL VX _IRQ _RESET NC NC VCC OSCI OSCO EKC1 R7
C4A C5 C6 C7 VSS/GND NC C15 C14 C13 C12 C11
R6 RP KD KC EKC EKD CL C0 C1 C2 C3
1
QFP
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 DOC5-418-DS-109
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www.semtech.com
C4 C5 C6 C7 NC VSS/GND C15 C14 C13 C12 NC
ORDERING CODE
Package options 40-pin, Plastic DIP 44-pin, Plastic PLCC 44-pin, Plastic QFP Pitch in mm’s 2.54 1.27 0.8 TA = -40°C to +85°C UR5HC418-P UR5HC418-FN UR5HC418-FB
FUNCTIONAL DI.