The MC74LS164 is an 8-bit serial-in, parallel-out shift register manufactured by Freescale Semiconductor (NXP). It is a member of the 74LS family of TTL logic devices. This device accepts serial data input and shifts it through the register with each clock pulse. After eight clock pulses, the data is available in parallel form at the eight output pins.

Applications

• Serial-to-Parallel Conversion: Converts serial data streams into parallel data for driving displays, memory, or other parallel-input devices.
• Data Delay: Introduces a controlled delay in a digital signal path.
• Display Driving: Drives LED or other types of displays by converting serial data into parallel data for each segment or pixel.
• Keyboard Scanning: Scanning rows and columns of a keyboard to detect key presses.
• Sequence Generation: Generates specific binary sequences by manipulating the serial input data.

Features

• 8-Bit Shift Register: Stores and shifts 8 bits of data.
• Serial Input: Accepts data serially on two input pins (A and B) which are ANDed together internally.
• Parallel Outputs: Provides parallel access to all 8 bits of stored data.
• Asynchronous Clear: A clear input that allows the register to be reset to all zeros regardless of the clock state.
• Low-Power Schottky (LS) Technology: Provides a good balance between speed and power consumption.
• TTL Compatible: Interfaces easily with other TTL logic devices.

Benefits

• Efficient Serial-to-Parallel Conversion: Simplifies interfacing between serial data sources and parallel data processing systems.
• Reduced Wiring: Requires only a few wires for data transmission, reducing complexity and cost.
• Flexible Data Manipulation: Allows for easy manipulation and control of digital data.
• Simplified Display Control: Enables simple control of multiple LEDs or display segments with minimal circuitry.
• Reliable Operation: Provides stable and predictable performance in various digital systems.

The MC74LS164 is available in various package types, including DIP (Dual In-Line Package) and SOIC (Small Outline Integrated Circuit). It is commonly used in applications where data needs to be transferred serially over a distance and then converted to parallel form for processing or display. The asynchronous clear input provides a convenient way to reset the register to a known state. The A and B serial inputs are internally ANDed, meaning that both inputs must be high for data to be shifted into the register.