How do IO devices communicate with CPU?

How do IO devices communicate with CPU?

To communicate with a particular device, the processor places a device address on address lines. Each Interface decodes the address and control received from the I/O bus, interprets them for peripherals and provides signals for the peripheral controller.

Which bus transfer the address information to the I O device?

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.

How the processor is physically connected to memory and input output?

A control bus is a computer bus that is used by the CPU to communicate with devices that are contained within the computer. This occurs through physical connections such as cables or printed circuits. When the CPU writes data to the main memory, it transmits a signal to the write command line.

When a peripheral device is connected with microprocessor in input output mode the data transfer takes place?

In this mode of data transfer the operations are the results in I/O instructions which is a part of computer program. Each data transfer is initiated by an instruction in the program. Normally the transfer is from a CPU register (Accumulator) to peripheral I/O device or vice-versa.

How many peripheral IO ports does a computer have?

Up to 16 IEEE 1394 devices can be connected to a single IEEE 1394 port through daisy-chaining. Most external IEEE 1394 devices have two ports to enable daisy-chaining.

How many main groups of IO devices are there?

The responsibility of I/O is to interface with external devices. Depending on their applications, I/O operations can be divided into three groups: sensory input, control output, and data transfer.

Why are I O devices not directly connected to the CPU system bus?

External devices are not connected directly to the system bus because they have a wide range of control logics, as well as data transfer speeds and formats. Virtually all external devices have buffers, control signals, status signals, and data bits.

Why I O devices Cannot be connected directly to processor give any two reasons?

Each I/O module interfaces to the system bus and controls one or more peripheral devices. There are several reasons why an I/O device or peripheral device is not directly connected to the system bus.  The data transfer rate of peripherals is often much slower than that of the memory or processor.

Why I O modules is needed between system bus and I O devices?

An I/O module is needed because of : (a) Diversity and variety of I/O devices makes it difficult to incorporate all the peripheral device logic (i.e. its control commands, data format etc.) into CPU. It controls the data exchange between the external devices and main memory; or external devices and CPU registers.

How many peripheral input ports does a computer have?

On the back of computers are several I/O, (or Input/Output), ports. Above, on the very top are two PS/2 ports, normally used for mouse and keyboard connections. Below that are the USB, (or Universal Serial Bus), ports.

How are different I O ports addressed in computers?

Internal port − It connects the motherboard to internal devices like hard disk drive, CD drive, internal modem, etc. External port − It connects the motherboard to external devices like modem, mouse, printer, flash drives, etc.

How many I O ports are placed in microcontroller 8051?

4 I/O ports
8051 microcontrollers have 4 I/O ports each of 8-bit, which can be configured as input or output.