
ON Semiconductor
8-BIT SHIFT REGISTERS
The SN74LS166 is an 8-Bit Shift Register. Designed with all inputs buffered, the drive requirements are lowered to one 74LS standard load. By utilizing input clamping diodes, switching transients are minimized and system design simplified.
The LS166 is a parallel-in or serial-in, serial-out shift register and has a complexity of 77 equivalent gates with gated clock inputs and an overriding clear input. The shift/load input establishes the parallel-in or serial-in mode. When high, this input enables the serial data input and couples the eight flip-flops for serial shifting with each clock pulse. Synchronous loading occurs on the next clock pulse when this is low and the parallel data inputs are enabled. Serial data flow is inhibited during parallel loading. Clocking is done on the low-to-high level edge of the clock pulse via a two input positive NOR gate, which permits one input to be used as a clock enable or clock inhibit function.
• Synchronous Load
• Direct Overriding Clear
• Parallel to Serial Conversion