DMA CONTROLLER
ARCHITECTURE OF 8085
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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DMA Controller
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Programmable Input Output
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Programmable Interval Timer
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Programmable Interrupt Controller
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Detailed explanation-1: -DMA stands for Direct Memory Access. It is designed by Intel to transfer data at the fastest rate. It allows the device to transfer the data directly to/from memory without any interference of the CPU.
Detailed explanation-2: -The term DMA stands for direct memory access. The hardware device used for direct memory access is called the DMA controller. DMA controller is a control unit, part of I/O device’s interface circuit, which can transfer blocks of data between I/O devices and main memory with minimal intervention from the processor.
Detailed explanation-3: -The controller notifies the DSP processor that it is ready for a transfer. Then the processor relinquishes control of its external memory bus and grants the control of the bus to the DMA controller. The DMA controller then transfers the specified amount of data and signals the processor upon completion of the transfer.
Detailed explanation-4: -In the cycle stealing mode, the DMA controller obtains access to the system bus the same way as in burst mode, using BR (Bus Request) and BG (Bus Grant) signals, which are the two signals controlling the interface between the CPU and the DMA controller.
Detailed explanation-5: -Direct Memory Access (DMA) is a data transfer strategy that bypasses the CPU, instead using a dedicated DMA controller to transfer data between memory and a device. Drivers can use the DMA controller to transfer data directly.