Is my flowchart for programmed io and interrput drive io correct?

Thread Starter

terabaaphoonmein

Joined Jul 19, 2020
15
Source of my knowledge-: https://electronics.stackexchange.com/questions/204337/programmed-io-vs-interrupt-for-devices
https://slideplayer.com/slide/265620/

And my teacher.

So here is what I understand about

1) Programmed IO-:
Here CPU periodically executes instruction which reads READY pin

2) Interrupt driven IO-:
Here CPU checks interrupt at the end of each instruction cycle whereas IO device sends interrupt.
The original flowchart for these are as follows-:
1634909659486.png


Here is what I have made-:

Programmed IO-:
1634909720716.png

interrupt driven io-:
1634909777954.png

I just want to know if my understanding of flowchart is correct or not?
 

MrChips

Joined Oct 2, 2009
24,623
For starters, a diamond shape is used for representing the IF-THEN-ELSE control structure.
You cannot have three exit points from the structure.

Programmed I/O or interrupt driven I/O can take two forms, blocking and non-blocking.
Blocking means while a condition is being tested no other process can take place.
Non-blocking means that while waiting for an event to happen the CPU can continue with other processes.
You need to choose one or the other.
 

BobaMosfet

Joined Jul 1, 2009
1,898
Source of my knowledge-: https://electronics.stackexchange.com/questions/204337/programmed-io-vs-interrupt-for-devices
https://slideplayer.com/slide/265620/

And my teacher.

So here is what I understand about

1) Programmed IO-:
Here CPU periodically executes instruction which reads READY pin

2) Interrupt driven IO-:
Here CPU checks interrupt at the end of each instruction cycle whereas IO device sends interrupt.
The original flowchart for these are as follows-:
View attachment 250837


Here is what I have made-:

Programmed IO-:
View attachment 250838

interrupt driven io-:
View attachment 250839

I just want to know if my understanding of flowchart is correct or not?
I guess the obvious question is- why are you looking at 1 flow chart that makes sense, and rewriting it? You should be able to easily understand the original flow-chart....
 
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