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SN54/74LS166
8-BIT SHIFT REGISTERS
The SN54L/ 74LS166 is an 8-Bit Shift Register. Designed with all inputs
buffered, the drive requirements are lowered to one 54 / 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 8-BIT SHIFT REGISTERS
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. LOW POWER SCHOTTKY
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 J SUFFIX
function. Clocking is inhibited when either of the clock inputs are held high, CERAMIC
holding either input low enables the other clock input. This will allow the CASE 620-09
system clock to be free running and the register stopped on command with 16
1
the other clock input. A change from low-to-high on the clock inhibit input
should only be done when the clock input is high. A buffered direct clear input
overrides all other inputs, including the clock, and sets all flip-flops to zero.