Question

Consider a hypothetical processor which supports a maximum of 512 MB of byte addressable memory. Processor uses memory mapped I/O configuration: in which 3 most significant bits of address needs to be zero to assign the address to I/O-port. How many number of port addresses (I/O addresses) and memory addresses possible in the processor respectively?

• A. $1\times 2^{26}and7\times 2^{26}$
• B. $2^{26}and{2}^{29}$
• C. $1\times 2^{26}and3\times 2^{26}$
• D. $1\times 2^{29}and7\times 2^{29}$

Answer 1

The correct option is A $1\times 2^{26}and7\times 2^{26}$

option (b)
For memory size 512 MB ( = $2^{29}$B) address size = 29-bits.

Assume address bits are: