SN54ALS193A

SN54ALS193A, SN74ALS193A SYNCHRONOUS 4ĆBIT UP/DOWN BINARY COUNTERS WITH DUAL CLOCK AND CLEAR SDAS211C − DECEMBER 1982 − REVISED JULY 1996 D Look-Ahead Circuitry Enhances Cascaded Counters D Fully Synchronous in Count Modes D Parallel Asynchronous Load for Modulo-N Count Lengths D Asynchronous Clear D Package Options Include Plastic Small-Outline (D) Packages, Ceramic Chip Carriers (FK), and Standard Plastic (N) and Ceramic (J) 300-mil DIPs description The ’ALS193A are synchronous, reversible, 4-bit up/down binary counters. Synchronous counting operation is provided by having all flip-flops clocked simultaneously so that the outputs change coincident with each other when instructed by the steering logic. This mode of operation eliminates the output counting spikes normally associated with asynchronous (rippleclock) counters. The outputs of the four flip-flops are triggered on a low-to-high-level transition of either count/clock (UP or DOWN) input. The direction of the count is determined by which count input is pulsed while the other count input is high. SN54ALS193A . . . J PACKAGE SN74ALS193A . . . D OR N PACKAGE (TOP VIEW) B1 QB 2 QA 3 DOWN 4 UP 5 QC 6 QD 7 GND 8 16 VCC 15 A 14 CLR 13 BO 12 CO 11 LOAD 10 C 9D SN54ALS193A . . . FK PACKAGE (TOP VIEW) VCC NC QB A B QA DOWN NC UP QC 3 2 1 20 19 4 18 5 17 6 16 7 15 8 14 9 10 11 12 13 CLR BO NC CO LOAD C D NC GND QD NC − No internal connection All four counters are fully programmable; that is, each o...