LS7056

LSI/CSI UL ® LS7055 LS7056 (631) 271-0400 FAX (631) 271-0405 January 2003 LSI Computer Systems, Inc. 1235 Walt Whitman Road, Melville, NY 11747 A3800 6 DECADE PREDETERMINING UP/DOWN COUNTER FEATURES: +4.75V to +15V (Vss - VDD) Preset, Presignal and Mainsignal Store DC to 250kHz Count Frequency Fully Synchronous Operation Three Comparators with Output Flags Automatic or Manual Preset/Reset Control Thumbwheel Interface for Storage Selects Prescale on Count Input Selectable Count Inhibit Up/Down Control Scan Rate up to 150kHz Scan Oscillator has Override Capability Blanking Override for Decimal Point Operaton Multiplexed 7 Segment and BCD Data Output Output latches Reset Hysteresis on Count Input CMOS Type Noise Immunity on all other inputs LS7055, LS7056 (DIP) - See Figure 1 DESCRIPTION: The LS7055/LS7056 is a MOS synchronous 6 decade Up/Down counter. The circuit includes storages and comparators, zero detect, automatic presetting and resetting, output latches, multiplexed output BCD and seven segment data. Thumbwheel switches can be used to provide BCD data to the storage networks in the circuit. COUNT (Pin 40) Counter operates at speeds up to 250kHz and advances on the positive edge of the input count pulse. UP/DOWN (Pin 39) Counter operates in up or down mode. A high input causes the counter to operate in the up mode while a low input causes it to operate in the down mode. COUNT INHIBIT (Pin 1) A high input inhibits counting and the coun...