Computer Organization and Architecture Lecture 20

Addressing Modes

Mode is nothing but a way of addressing the memory. There are different ways to address the memory. The different ways of addressing the memory are called addressing modes.

• Implied Mode
• Immediate Mode
• Register Mode

When memory size is 1mb we have $2^{20}$ locations. The memory has $20$ address bits. so its split into 4 parts. The first 4 bits are used to select the memory bank. The next 6 bits are used to select the row. The next 6 bits are used to select the column. The last 4 bits are used to select the word.

Instruction size can be 1,2,3,4 bytes long. The instruction size is 2 bytes long. Instruction queue can only store complete intructions.

BIU

• Instruction streaembyte queue
• A set of segment registers
• Instruction Pointer

If BIU has 6 bytes and 2,3 bytes instructions come and sit a 2 byte cant come to occupy.d

References

Information

• date: 2025.03.12
• time: 09:41