Monday, September 12, 2005
Input output interface
TWO MARK QUESTIONS:
1) What is the use of input-output interface?
Input-output interface supports information transfer between internal storage and external I/O devices. Interface units act as special links for resolving the difference in the characteristics of internal devices and external devices.
2) What is the need for interface unit (or) what are the major differences between central computer and peripherals?
i) The electromechanical (use voltage) peripherals and electronic (use charge) memory and CPU have difference in their operations. Hence conversion of signals is necessary.
ii) Data transfer in peripherals is slower than that in CPU. To provide a synchronization mechanism, interface unit is needed.
iii) The data codes and formats differ from word formats in CPU and memory.
iv) Operating modes are different from other. Interface unit is necessary , not to disturb the operation of the other peripheral.
3) What are interface units?
Interface units are special hardware components between CPU and the peripherals to supervise, synchronize all input and output transfers. They serve as interface between the processor bus and peripheral devices.
4) What are the four types of commands an interface may receive?
i) Control command – To activate peripheral and inform what to do
ii) Status command- Test the conditions in interface and peripheral
iii) Data output command-To transfer data from bus to one of its registers
iv) Data input command-To receive an item of data from peripheral and place it in the buffer register
5) What is IOP? What is the use of IOP? Or What is data channel? What is the use of data channel?
The systems with independent sets of data, address and control bus use separate I/O processor (IOP) along with CPU. IOP communicate with I/O bus. It provides independent pathway for transfer of information between external devices and internal memory.
6) What is isolated I/O?
The devices using common bus for both memory and I/O but with separate control lines for memory and CPU. CPU enables the appropriate control line’s read and write signals when the address is kept on the address line. This isolate I/O interface address from memory address. This method of assigning address in common bus is called isolated I/O method.
7) What is memory mapped I/O?
The computers using common bus for memory and I/O with common control lines use only one set of read and write signals and do not distinguish between memory and I/O address. This configuration is referred to as memory-mapped I/O.
8) What are the differences between isolated I/O and memory mapped I/O?
Isolated I/O configuration uses common bus but separate control lines. Memory-mapped I/O uses common bus and common control lines.
Isolated I/O has separate address space
Memory-mapped I/O has common address space
Isolated I/O use separate instruction sets.
Memory-mapped I/O use the common instruction set.
OTHER QUESTIONS:
1) Explain Input output interface with example (16 marks)
2) Briefly explain I/O bus and interface modules. (8 marks)
3) Explain Isolated I/O and memory-mapped I/O.What are the differences between Isolated I/O and memory-mapped I/O? What are the advantages and disadvantages of each? (8 marks)
4) Give an example of I/O interface with example. (8 marks) ¶ 11:15 AM
1) What is the use of input-output interface?
Input-output interface supports information transfer between internal storage and external I/O devices. Interface units act as special links for resolving the difference in the characteristics of internal devices and external devices.
2) What is the need for interface unit (or) what are the major differences between central computer and peripherals?
i) The electromechanical (use voltage) peripherals and electronic (use charge) memory and CPU have difference in their operations. Hence conversion of signals is necessary.
ii) Data transfer in peripherals is slower than that in CPU. To provide a synchronization mechanism, interface unit is needed.
iii) The data codes and formats differ from word formats in CPU and memory.
iv) Operating modes are different from other. Interface unit is necessary , not to disturb the operation of the other peripheral.
3) What are interface units?
Interface units are special hardware components between CPU and the peripherals to supervise, synchronize all input and output transfers. They serve as interface between the processor bus and peripheral devices.
4) What are the four types of commands an interface may receive?
i) Control command – To activate peripheral and inform what to do
ii) Status command- Test the conditions in interface and peripheral
iii) Data output command-To transfer data from bus to one of its registers
iv) Data input command-To receive an item of data from peripheral and place it in the buffer register
5) What is IOP? What is the use of IOP? Or What is data channel? What is the use of data channel?
The systems with independent sets of data, address and control bus use separate I/O processor (IOP) along with CPU. IOP communicate with I/O bus. It provides independent pathway for transfer of information between external devices and internal memory.
6) What is isolated I/O?
The devices using common bus for both memory and I/O but with separate control lines for memory and CPU. CPU enables the appropriate control line’s read and write signals when the address is kept on the address line. This isolate I/O interface address from memory address. This method of assigning address in common bus is called isolated I/O method.
7) What is memory mapped I/O?
The computers using common bus for memory and I/O with common control lines use only one set of read and write signals and do not distinguish between memory and I/O address. This configuration is referred to as memory-mapped I/O.
8) What are the differences between isolated I/O and memory mapped I/O?
Isolated I/O configuration uses common bus but separate control lines. Memory-mapped I/O uses common bus and common control lines.
Isolated I/O has separate address space
Memory-mapped I/O has common address space
Isolated I/O use separate instruction sets.
Memory-mapped I/O use the common instruction set.
OTHER QUESTIONS:
1) Explain Input output interface with example (16 marks)
2) Briefly explain I/O bus and interface modules. (8 marks)
3) Explain Isolated I/O and memory-mapped I/O.What are the differences between Isolated I/O and memory-mapped I/O? What are the advantages and disadvantages of each? (8 marks)
4) Give an example of I/O interface with example. (8 marks) ¶ 11:15 AM
