Simulator for 8085 microprocessor

 Download GNUSim8085

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Memory mapped I/O and Isolated I/O

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As a CPU needs to communicate with the various memory and input-output devices (I/O) as we know data between the processor and these devices flow with the help of the system bus. There are three ways in which system bus can be allotted to them : Separate set of address, control and data bus to I/O and memory. Have common bus (data and address) for I/O and memory but separate control lines. Have common bus (data, address, and control) for I/O and memory. In first case it is simple because both have different set of address space and instruction but require more buses. Isolated I/O – Then we have Isolated I/O in which we Have common bus(data and address) for I/O and memory but separate read and write control lines for I/O. So when CPU decode instruction then if data is for I/O then it places the address on the address line and set I/O read or write control line on due to which data transfer occurs between CPU and I/O. As the address space of memory and I/O is isolated and the name is so....
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Assignment Questions (Subject:- Microprocessor and Its Interfacing)

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8237 Direct Memory Access (DMA) Controller

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