serialinparallelout

Serial-In Parallel-Out (SIPO) refers to a class of shift registers that convert a serial data stream into parallel data. Data is received on a single input and, on each clock edge, is shifted into successive storage elements. After a sequence of clock pulses equal to the desired width, the parallel outputs reveal the stored bits simultaneously. Some variants include a storage or latch stage that can capture the parallel data and present it to the outputs independent of subsequent shifts.

Operation: A typical SIPO device comprises a chain of flip-flops with a serial input, a clock input, and a bank of parallel outputs. The serial input receives the first bit; the clock shifts it into the first stage, while previously stored bits march toward later stages. The outputs reflect the current contents. Many devices feature additional control signals such as clear/reset, enable, and an output latch or tri-state enable to hold or deactivate outputs.

Common usage: SIPO shift registers are used to convert serial data to parallel form for downstream devices, such as LED bar graphs, display drivers, or microcontroller port extension. They enable economical interfaces from a microcontroller’s serial peripherals to wider parallel loads and can be cascaded to create larger widths.

See also: Parallel-in Serial-out (PISO), Serial-in Serial-out (SISO), and Parallel-in Parallel-out (PIPO). A widely known example is the 74HC595, an 8-bit SIPO with a storage latch used to drive LEDs.