February 18th, 2013, 08:15 AM

I am new to operating system and i got some Questions about pipeling
Firstly ,the question we have A processor has 24 registers*, uses 8bit immediate*, and has 36 different instructions* (corresponding to 36 operation codes**) in its instruction set.These 36 instructions are classified into 4 types as listed belowi just going to give out type c)
TypeC: takes 1 source register, 1 immediate, uses 1 destination register;
i know how to do this but the problem here is i don't know how many bit do 24 registers and 36 opcode require
(? = unknown)
i know the answer will be ?opcode+ ?registers + 8bits immediates + ?registers = bits
But i'd like to know how do i calculate the bits require
Secondly, there's question asking me how much the pipeline speedup ratio:
Code:
Assume a pipelined processor operates in four states: instruction fetch (IF), operand fetch (OF), operand execute (OE), and operand store (OS). A timing diagram of pipeline could be drawn as follows:
we have the following code with the data dependency.
ADD R1,R3,R2 [R1] ← [R3]+[R2]
SUB R4,R1,R5 [R4] ← [R1][R5]
MUL R6,R7,R8 [R6] ← [R7]*[R8]
This is the table :
Cycle 0 cycle 1 cycle 2 cycle 3 cycle 4 cycle 5 cycle 6 ......
IF
ADD R1,R2,R3 IF OF OE OS
ADD
R1,R3,R2 IF OF OE OS
SUB
R4,R1,R5 IF OF OE OS
MUL
R6,R7,R8 IF OF OE OS
And this is all the information i get , but i don't know how many instruction in here also i don't know the Clock speed, how can i bring out the speed up ratio?
Many thanks for reply or view
my lecturer never reply my email sigh...
February 26th, 2013, 07:11 PM

erm....
I think is correct I'm not too sure but this is what I have done. Basically if the register was 32 it would be 2^5 and if the instructions were 64 it would 2^6
so for c it would be:
6opcode+ 5registers + 8bits immediates + 5registers = 24bits/3bytes
If the numbers don't fit in base two exactly e.g 36 doesn't but
the closest to it is 2^5 we use that
Also if you get say 21bits you round it up to 24bits so its 3bytes bits should always be divided by 8.