Bit-serial architecture

Computational system in which data are sent one bit at a time down a wire

In computer architecture, bit-serial architectures send data one bit at a time, along a single wire, in contrast to bit-parallel word architectures, in which data values are sent all bits or a word at once along a group of wires.

All digital computers built before 1951, and most of the early massive parallel processing machines used a bit-serial architecture—they were serial computers.

Bit-serial architectures were developed for digital signal processing in the 1960s through 1980s, including efficient structures for bit-serial multiplication and accumulation.^[1]

The HP Nut processor used in many Hewlett-Packard calculators operated bit-serially.^[2]

Often, N serial processors will take less FPGA area and have a higher total performance than a single N-bit parallel processor.^[3]

References

^ Denyer, Peter B.; Renshaw, David (1985). VLSI signal processing: a bit-serial approach. VLSI systems series. Addison-Wesley. ISBN 978-0-201-13306-6.
^ Smith, Eric L. "brouhaha" (2023-08-09). "HP-15C CE woes: 1 bug, 2 limitations, 3 questions". MoHPC - The Museum of HP Calculators. Archived from the original on 2023-08-10. Retrieved 2023-09-24.
^ Andraka., Raymond J. "Building a High Performance Bit Serial Processor in an FPGA" (PDF).

External links

Application of FPGA technology to accelerate the finite-difference time-domain (FDTD) method
BIT-Serial FIR filters with CSD Coefficients for FPGAs

Processor technologies

Models

Abstract machine
Stored-program computer
Finite-state machine
- with datapath
- Hierarchical
- Deterministic finite automaton
- Queue automaton
- Cellular automaton
- Quantum cellular automaton
Turing machine
Belt machine
Stack machine
Register machines

Architecture

Instruction set
architectures

Types	Orthogonal instruction set CISC RISC Application-specific EDGE TRIPS VLIW EPIC MISC OISC NISC ZISC VISC architecture Quantum computing Comparison Addressing modes
Instruction sets	Motorola 68000 series VAX PDP-11 x86 ARM Stanford MIPS MIPS MIPS-X Power POWER PowerPC Power ISA Clipper architecture SPARC SuperH DEC Alpha ETRAX CRIS M32R Unicore Itanium OpenRISC RISC-V MicroBlaze LMC System/3x0 S/360 S/370 S/390 z/Architecture Tilera ISA VISC architecture Epiphany architecture Others

Execution

Instruction pipelining	Pipeline stall Operand forwarding Classic RISC pipeline
Hazards	Data dependency Structural Control False sharing
Out-of-order	Scoreboarding Tomasulo's algorithm Reservation station Re-order buffer Register renaming Wide-issue
Speculative	Branch prediction Memory dependence prediction

Parallelism

Level	Bit Bit-serial Word Instruction Pipelining Scalar Superscalar Task Thread Process Data Vector Memory Distributed
Multithreading	Temporal Simultaneous Hyperthreading Simultaneous and heterogenous Speculative Preemptive Cooperative
Flynn's taxonomy	SISD SIMD Array processing (SIMT) Pipelined processing Associative processing SWAR MISD MIMD SPMD

Processor
performance

Transistor count
Instructions per cycle (IPC)
- Cycles per instruction (CPI)
Instructions per second (IPS)
Floating-point operations per second (FLOPS)
Transactions per second (TPS)
Synaptic updates per second (SUPS)
Performance per watt (PPW)
Cache performance metrics
Computer performance by orders of magnitude

Types

By application	Embedded system Microprocessor Microcontroller Mobile Ultra-low-voltage ASIP Soft microprocessor
Systems on chip	System on a chip (SoC) Multiprocessor (MPSoC) Programmable (PSoC) Network on a chip (NoC)
Hardware accelerators	Coprocessor AI accelerator Graphics processing unit (GPU) Image processor Vision processing unit (VPU) Physics processing unit (PPU) Digital signal processor (DSP) Tensor Processing Unit (TPU) Secure cryptoprocessor Network processor Baseband processor

Word size

Core count

Components

Functional units	Arithmetic logic unit (ALU) Address generation unit (AGU) Floating-point unit (FPU) Memory management unit (MMU) Load–store unit Translation lookaside buffer (TLB) Branch predictor Branch target predictor Integrated memory controller (IMC) Memory management unit Instruction decoder
Logic	Combinational Sequential Glue Logic gate Quantum Array
Registers	Processor register Status register Stack register Register file Memory buffer Memory address register Program counter
Control unit	Hardwired control unit Instruction unit Data buffer Write buffer Microcode ROM Counter
Datapath	Multiplexer Demultiplexer Adder Multiplier CPU Binary decoder Address decoder Sum-addressed decoder Barrel shifter
Circuitry	Integrated circuit 3D Mixed-signal Power management Boolean Digital Analog Quantum Switch