54AC299 Datasheet | National Semiconductor

Description The ’AC/’ACT299 is an 8-bit universal shift/storage register with TRI-STATE ® outputs. Four modes of operation are possible: hold (store), shift left, shift right and load data. The parallel load inputs and flip-flop outputs are multiplexed to reduce the total number of package pins. Additional outputs are provided for flip-flops Q0, Q7 to allow easy serial cascading. A separate active LOW Master Reset is used to reset the register. n mon parallel I/O for reduced pin count n Additional serial inputs and outputs for expansion n Four operating modes: shift left, shift right, load and store n TRI-STATE outputs for bus-oriented applications n Outputs source/sink 24 m A n ’ACT299 has TTL-patible inputs n Standard Microcircuit Drawing (SMD) ’AC299: 5962-88754 ’ACT299: 5962-88771 Features n ICC and IOZ reduced by 50% Ordering Code: Logic Symbols Connection Diagrams Pin Assignment for DIP and Flatpak DS100252-1 IEEE/IEC DS100252-2 Pin Assignment for LCC DS100252-3 DS100252-4 TRI-STATE ® is a registered trademark of National Semiconductor Corporation. FACT ® is a registered trademark of Fairchild Semiconductor Corporation. © 1998 National Semiconductor Corporation DS100252 .national. Connection Diagrams Pin Names CP DS0 DS7 S0, S1 MR OE1, OE2 I/O0- I/O7 Q0, Q7 (Continued) Description Clock Pulse Input Serial Data Input for Right Shift Serial Data Input for Left Shift Mode Select Inputs Asynchronous Master Reset TRI-STATE Output Enable Inputs Parallel Data Inputs or TRI-STATE Parallel Outputs Serial Outputs Functional Description The ’AC/’ACT299 contains eight edge-triggered D-type flip-flops and the interstage logic necessary to perform synchronous shift left, shift right, parallel load and hold operations. The type of operation is determined by S0 and S1, as shown in the Truth Table. All flip-flop outputs are brought out through TRI-STATE buffers to separate I/O pins that also serve as data inputs in the parallel load mode. Q0 and Q7 are also...