1. What are the advantages and disadvantages of hardwired and micro-programmed control? 2. Why is micro-programmed control becoming increasingly popular? Please type answer Solution A hardwired control unit has a processor that generates signals or instructions to be implemented in correct sequence. This was the older method of control that works through the use of distinct components like a sequential circuit or combinational circuit or flip-flops. The control unit is implemented using hardware like NAND gates and counters. advantage of hardwired control is that it is very fast The disadvantage is that the instructions set and the control logic are directly tied together by special circuits that are complex and difficult to design or modify. To modify a existing circuit we need to have new chips that need to be replaced and it is very expensive Micro programming is a second alternative for designing the control unit. A control unit whose binary control variables are stored in memory is called a micro programmed control unit. The control variables at any given time can be represented by a string of 1\'s and 0\'s called a control word which can be programmed to perform various operations on the components of sys. Advantages are only thing that needs to be modified is software code. No hardware changes needed. It is flexible and easy to design. Disadvantages are it is slow as all instructions must go through an additional level of interpretation and development is expensive due to software tools Micro-programmed control is becoming popular due to Relatively simple logic circuit that is capable of sequencing through micro instructions and generating control signal to execute each micro instruction. It acts as a device supervisor that controls the rest of the subsystem including arithmetic and logical unit, registers, buses etc. Micro programming can sometimes develop two quite different architectures appear identical on a binary code level which are used In mainframes, mini computers and even micro processors. Some complex instructions in the pentium instruction set are executed using micro programing. Micro programming is used in defence applications,developing special purpose machines etc.

1. 1. What are the advantages and disadvantages of hardwired and micro-programmed control?
2. Why is micro-programmed control becoming increasingly popular?
Please type answer
Solution
A hardwired control unit has a processor that generates signals or instructions to be implemented
in correct sequence. This was the older method of control that works through the use of distinct
components like a sequential circuit or combinational circuit or flip-flops. The control unit is
implemented using hardware like NAND gates and counters.
advantage of hardwired control is that it is very fast
The disadvantage is that the instructions set and the control logic are directly tied together by
special circuits that are complex and difficult to design or modify. To modify a existing circuit
we need to have new chips that need to be replaced and it is very expensive
Micro programming is a second alternative for designing the control unit. A control unit whose
binary control variables are stored in memory is called a micro programmed control unit. The
control variables at any given time can be represented by a string of 1's and 0's called a control
word which can be programmed to perform various operations on the components of sys.
Advantages are only thing that needs to be modified is software code. No hardware changes
needed. It is flexible and easy to design. Disadvantages are it is slow as all instructions must go
through an additional level of interpretation and development is expensive due to software tools
Micro-programmed control is becoming popular due to
Relatively simple logic circuit that is capable of sequencing through micro instructions and
generating control signal to execute each micro instruction. It acts as a device supervisor that
controls the rest of the subsystem including arithmetic and logical unit, registers, buses etc.
Micro programming can sometimes develop two quite different architectures appear identical on
a binary code level which are used In mainframes, mini computers and even micro processors.
Some complex instructions in the pentium instruction set are executed using micro programing.
Micro programming is used in defence applications,developing special purpose machines etc