Question

There are 3 forms of Program Memory Addressing Modes: Direct, Relative, and Indirect. Explain/Illustrate what happens to CS and IP registers if the JMP THERE instruction is stored at memory address 10000H (CS=1000H, IP=0000H) and the address of THERE is:
(A) 10020H
(B) 30000H

Answer 1

• CS is code segment register & IP is instruction pointer register.
• IP register stores the offset address of the next instruction to be executed.
• CS is used for addressing memory location in the code segment of the memory, where the executable program is stored.The processor uses CS segment for all accesses to instructions referenced by instruction pointer (IP) register.
• Initially the values of CS=1000H & IP=0000H
• When JMP THERE instruction is to be excuted

CASE1: when THERE = 10020H

Content of IP will change initially to 10020 H & the data or content of memory location 10020 H will be loaded into CS register for segmentation.

CASE2: when THERE = 30000H

Content of IP will change initially to 30000 H & the data or content of memory location 30000 H will be loaded into CS register for segmentation.