Multi-master bus

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A multi-master bus is a computer bus in which there are multiple bus master nodes present on the bus. This is used when multiple nodes on the bus must initiate transfer. For example, direct memory access (DMA) is used to transfer data between peripherals and memory without the need to use the central processing unit (CPU).

In computing, bus mastering is a feature supported by many bus architectures that enables a device connected to the bus to initiate direct memory access (DMA) transactions. It is also referred to as first-party DMA, in contrast with third-party DMA where a system DMA controller actually does the transfer.

Direct memory access (DMA) is a feature of computer systems that allows certain hardware subsystems to access main system memory, independent of the central processing unit (CPU).

Central processing unit electronic circuitry within a computer that carries out the instructions of a computer program by performing the basic arithmetic, logical, control and input/output (I/O) operations specified by the instructions

A central processing unit (CPU), also called a central processor or main processor, is the electronic circuitry within a computer that carries out the instructions of a computer program by performing the basic arithmetic, logic, controlling, and input/output (I/O) operations specified by the instructions. The computer industry has used the term "central processing unit" at least since the early 1960s. Traditionally, the term "CPU" refers to a processor, more specifically to its processing unit and control unit (CU), distinguishing these core elements of a computer from external components such as main memory and I/O circuitry.

Some buses like I²C use multi-mastering inherently to allow any node to initiate a transfer with another node.

I²C serial communication bus

I²C, pronounced I-squared-C, is a synchronous, multi-master, multi-slave, packet switched, single-ended, serial computer bus invented in 1982 by Philips Semiconductor. It is widely used for attaching lower-speed peripheral ICs to processors and microcontrollers in short-distance, intra-board communication. Alternatively I²C is spelled I2C or IIC.


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Multimaster or multi-master may refer to:

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