There is a clock signal in the micro controller.
Does the micro controller execute the instructions at the rising edge of the clock?
What is the significance of the duration of high and low time duration of the clock signal?
Why some instructions take only one cycle and others more.
One clock signal also involves the width of the clock signal?
Please advise.

Moderators note : placed questions on seperate lines

 

hi 77,
This link has some useful information.
https://www.computerhope.com/jargon/m/machcycl.htm
E

 

There is a clock signal in the micro controller. Does the micro controller execute the instructions at the rising edge of the clock? What is the significance of the duration of high and low time duration of the clock signal? Why some instructions take only one cycle and others more. One clock signal also involves the width of the clock signal? Please advise.

Pick a simple micro controller manual like the pic12f series.
After reading take an other mpu like Intel or Motorola and compare you will find some differences.
Don't get me wrong but your question is comparable to 'what type of engine is in a motorcar'?

Picbuster

 

There is a clock signal in the micro controller. 1) Does the micro controller execute the instructions at the rising edge of the clock? 2) What is the significance of the duration of high and low time duration of the clock signal? 3) Why some instructions take only one cycle and others more. 4) One clock signal also involves the width of the clock signal?

1) Depends on part, in general both edges used and pipelined parts can present with cycle skipping.

2) Basically mins in clock width controlled by propagation delays and on chip parasitic Capacitance.
Setup and hold time of clocked elements like flip flops, registers......

3) Depends on architecture, in general operations that require multiple memory accesses or
ones that test flags......

4) Not sure what question is, restate it another way.

Regards, Dana.

 

Their question is simply how does a processor use a square-wave to perform things. Even just instructions.

The answer is obvious- a square-wave is the lowest common denominator of 'state change' over time. (yes/no aka 1/0 but with a time factor added) Without which you cannot take steps to perform actions, or do them in uniform time-frames (regular clock cycle versus irregular). You can use leading edge, trailing edge, or both depending on need so long as it's done uniformly.

 

Does the micro controller execute the instructions at the rising edge of the clock?

No. They can execute on both edges and there are some "paths" that could be multi-cycle (cycles of the clock).

What is the significance of the duration of high and low time duration of the clock signal?

AFAIK, the duty cycle is close to 50%. It gives you more margin against clock jitter, setup/hold times, etc.

Why some instructions take only one cycle and others more.

It depends on the architecture.

One clock signal also involves the width of the clock signal?

The width of the clock cycle is determined by operating frequency.