Newnes Digital Logic IC Pocket Book

13

Latches, Registers, Comparators and Converters

Data latches and shift registers are widely used members of the flip-flop family of devices, and are often used in conjunction with logic comparators and code converters. This chapter looks at LS TTL and CMOS versions of all of these devices and shows how to use them.

Data Latches

Flip-flop circuit elements of the SET-RESET, D-type, and JK types (see Chapter 10) are often called ‘latches’, because their outputs can be latched into either a logic-0 or logic-1 state by applying suitable input signals. JK and D-type latches are fairly versatile elements, and can be made to act as either data latches or as divide-by-2 circuits by suitably connecting their input and output terminals. A pure ‘data ...