Memory mapped IO is an approach in which all IO data transfers are implemented by memory referencing instructions instead of IO instructions. This approach requires that memory locations and IO ports share the same set of address, so an address bit pattern that is assigned to memory cannot also be addressed to an IO port and vise versa.
2. What are the steps carried out during program execution?
Program execution is carried out as follows.
1. The CPU executes the instructions in their stored sequence except when the execution sequence is especially altered by a branch instruction.
2. The CPU transfers instructions and their input data from main memory to registers in the CPU.
3. When necessary, the CPU transfers output data from the CPU registers to main memory.
3. What is an IO mapped IO?
An IO mapped IO is a mapping approach in which all IO data transfers are implemented by IO instructions . These instructions produce control signals which IO ports, but not memory locations respond.
4. What are the programs that are executed by a general –purpose computer?
The programs executed by a general - purpose computer falls in two broad groups:
1. User programs
2. Supervisor programs.
5. Define an interrupt?
An interrupt is a request which can be received by the CPU for supervisor services directly from secondary memory units and other IO devises.
6. What is an emulator?
The set of micro programs that interpret a particular instruction set or machine language is called a emulator.
7. what is a micro assembler?
A micro assembler is a program used to translate micro programs into executable programs that can be stored in the control memory.
8. what are the approaches to control unit design?
There are 2 approaches to control unit design. These are
1. hard wired control
2. Micro programmed control
9. What are the types of instructions?
Instructions are divided into the following 5 types:
1. Data-transfer instructions.
2. Arithmetic instructions,
3. logical instructions
4. Program control instructions
5. Input output instructions
10. What are the design methods of hard wired control?
The design methods of hard wired control are
1. Classical method.
2. One hot method.
11 What is a round – off error?
A related issue in computer arithmetic is round – of error, which results from the fact that every number must be represented by a limited number of bits.
12. What are the types of micro instructions?
1. Horizontal microinstructions
2. Vertical microinstructions.
13. What are the two types of ALU expansion?
The two types of ALU expansion are
1. Spatial expansion.
2. Temporal expansion.
14. What are the types of phases?
1. Mono phase.
2. Poly phase.
15. What is an instruction pipeline?
An instruction pipeline is a multi function, reconfigurable pipeline designed to speed up a computer’s performance by efficiently overlapping the processing of instructions.
16. What is a hardwired control?
When the control signals are generated by hardware using conventional logic design techniques the control unit is said to be hard wired.
17. what is a micro programmed control unit?
A control unit whose binary controlled variables stored memory is called micro programmed control unit.
18 what is a pipeline control?
Where the control signals are generated by pipeline processing using conventional logic design techniques the control unit is said to be pipeline control.
19. what are the attributes if horizontal instructions?
1. Long formats
2. Ability to express a high degree of parallelism.
3. Little encoding of the control information.
20. What are the characteristics of vertical micro instructions?
1. Short formats
2. Limited ability to express parallel micro operations.
3. Considerable encoding of the control information.