Dynamic Shift Registers - Bitsavers - Trailing-Edge

MAPSMM5704AA MOS/LSI keyboard interface subsystemgeneral decriptionThe MM5704AA keyboard interface subsystem isa monolithic MaS/LSI circuit utilizing P-Channelenhancement mode low threshold voltage technology.It self-scans 32 dynamic keys (4 x 8matrix) and 8 static keys for switch closure. Thedynamic key positions are encoded into a 9-bitcode that is transmitted bit serial. The static keysare encoded into an 8-bit code. A read-only memoryallows customer programming of the charactercode for the 9-bit code. Control logic providesprogrammable delay times to match the switchbounce characteristics and key matrix capacjtancefor a wide selection of keyboard elements. Two"busy" lines are provided so several keyboardinterface chips can be paralleled to decode largerkey matrixes. Two key "roll over" is providedalong with positive lock-out for ambiguous keydepressions.features• Bipolar compatibility• Standard suppliesMinimum externalcomponents required+5V. -12V• Bit serial data transmission Uptoa9-bit code• Character code selection• Error-free decodeProgrammable charactercode ROMProvides two key"roll over" multiplekey lock-out by an alarmbusy line for activedecode indication• High speed0.75 MHz• Keyboard element fl-exibility Programmablekey bounce delayProgrammable keymatrix capacitance delayProgrammable keysfor alarm clearProgrammable idlekey reset delay• Large keyboard• Expandable• Timing control• Standard packageapplications• Keyboard decode• Binary multiplexer/encoder32 dynamic keys8 static keysBusy line ORed output(expandable in multiples of32 dynamic-8 static keys)Provides "character ready"command and respondson "transmit" command24-pin dual-in-linepackageTerminal interfaceCalculatorAccounting machineTypewriterBinary remotesensingblock and connection diagramsDual-In-Line Package2JilIIVlI """.,,"""CYClUI~RI(EII ,~ICM)CASlSlW~...!'+-____ I--'"I"'T'·-1- "IV .. 1213¢Cu-rNotol, .. svl ..' .."I2 ...