74F779 Datasheet | Fairchild Semiconductor

74F779 8-Bit Bidirectional Binary Counter with 3-STATE Outputs April 1988 Revised March 2000 74F779 8-Bit Bidirectional Binary Counter with 3-STATE Outputs General Description The 74F779 is a fully synchronous 8-stage up/down counter with multiplexed 3-STATE I/O ports for bus-oriented applications. All control functions (hold, count up, count down, synchronous load) are controlled by two mode pins (S0, S1). The device also Features carry lookahead for easy cascading. All state changes are initiated by the rising edge of the clock. Features s Multiplexed 3-STATE I/O ports s Built-in lookahead carry capability s Count frequency 100 MHz typ s Supply current 80 m A typ s Available in SOIC (300 mil only) Ordering Code: Order Number 74F779SC 74F779PC Package Number M16B N16E Package Description 16-Lead Small Outline Integrated Circuit (SOIC), JEDEC MS-013, 0.300 Wide 16-Lead Plastic Dual-In-Line Package (PDIP), JEDEC MS-001, 0.300 Wide Devices also available in Tape and Reel. Specify by appending the suffix letter “X” to the ordering code. Logic Symbol Connection Diagram © 2000 Fairchild Semiconductor Corporation DS009593 .fairchildsemi. Unit Loading/Fan Out Pin Names I/O0- I/O7 S0, S1 OE CET CP TC Data Inputs Data Outputs Select Inputs Output Enable Input (Active LOW) Count Enable Trickle Input (Active LOW) Clock Pulse Input (Active Rising Edge) Terminal Count Output (Active LOW) Description U.L. HIGH/LOW 0.25/0.33 75/15 (12.5) 0.25/0.33 0.25/0.33 0.25/0.33 0.25/0.33 25/12.5 Input IIH/IIL Output IOH/IOL 5 µA/- 0.2 m A - 3 m A/24 m A (20 m A) 5 µA/- 0.2 m A 5 µA/- 0.2 m A 5 µA/- 0.2 m A 5 µA/- 0.2 m A - 1 m A/20 m A Function Table S1 X X L (Not LL) H L L H S0 X X L CET X X X H L L OE H L H X X X CP X Function I/O0 to I/O7 in High Z Flip-Flop Outputs Appear on I/O Lines Parallel Load All Flip-Flops Hold (TC Held HIGH) Count Up Count Down H = HIGH Voltage Level L = LOW Voltage Level X = Immaterial = LOW-to-HIGH Clock Transition (Not LL) means S0 and S 1 should...