INSTRUCTION LENGTHG

Lecture 4: Instruction Length
By Noor Kadhum
Architecture For 2nd class- Computer Dep.
Babylon University -Sciences College For Women
------------------------------------------------------------------------------------
Instruction Length
instruction length is the number of bits or bytes which defines an instruction. This can be done simply by specifying how many bits in each field.The length of opcode field is Inferred from the No. of instruction supported by the processor to the form 2n , n will be the No. of bits for (opcode field):






The length of address field is inferred from memory which is formulated as 2n B or 2n W (30 KW, 256 MB, 1GB…..)
n will be the No. of bits in each address Field.

For example, if the memory size = 1 KB :
1K = 210 ? n= 10 ? address bits =10








The format of the instruction will be :


Think of the following:
Is it possible to store instructions on more than one memory location?
If your answer is "yes", can you formulate a mathematical equation that shows the relationship between the length of instruction and the number of memory locations occupied by the instruction?
Send your answer to the e-architecture class on Edmodo.