Okay so let me explain you a little what you have said.
You told us like if one is going for 4 year degree program (8 semester) one will have to renew his/her study permit before every semester. But the scenario is totally different.
Just take an example about FIC (Fraser International College) offers a pathway program help entry in SFU (Simon Fraser University) for low graders and the length of pathway is 1 year. While the offer letter clearly shows if the student scores higher than 3.2 GPA he will be transferred to SFU degree program of 4 years. CIC will issue that student 1 year Study Permit as his pathway's length is 1 year later once he finishes Pathway successfully he have to renew his permit for coming 2 years.
Now the other example is, one got direct admission in. just for say, Concordia University for 4 year degree program no pathway required to attend the degree program, hence, student will get 4 year study permit instead of for one semester as you said in your previous post.
I hope I make it very clear. if you still didnt got what I meant you may ask.