The CD74HCT40105MT is a 4-bit by 16-word high speed CMOS FIFO Register compatible with the CD40105B,except for "shift-out" circuitry. It is a low-power first-in-out (FIFO) "elastic" storage register that can store 16 four-bit words. The 40105 is capable of handling input and output data at different shifting rates. This feature makes particularly useful as a buffer between asynchronous systems. Each work position in the register is clocked by a control flip-flop, which stores a marker bit. A "1" signifies that the position"s data is filled and a "0" denotes a vacancy in that position. The control flip-flop detects the state of the preceding flip-flop and communicates its own status to the succeeding flip-flop. When a control flip-flop is in the "0" state and sees a "1" in the preceeding flip-flop, it generates a clock pulse that transfers data from the preceding four data latches into its own four data latches and resets the preceding flip-flop to "0".
Independent asynchronous inputs and outputs
Expandable in either direction
Reset capability
Status indicators on inputs and outputs
Shift-out independent of three-state control
Balanced propagation delay and transition times
Significant power reduction compared to LSTTL logic ICs
