Question

AL holds the hexadecimal value of 095h, what is the hexadecimal value for register EAX after executing the mnemonic opcode/operand instruction MOVSX EAX, AL? (This mnemonic opcode/operand instruction converts 8-bits to 32-bits)

Answer 1

The AL register is holds the 8 least significant bits of the EAX register.

Value in EAX = 095h = 95h = (1001 0101)₂

MOVSX EAX, AL

This instruction copies the value of AL into EAX and sign extends it to 32 bits

So, value in EAX is

(1111 1111 1111 1111 1111 1111 1001 0101)₂ = FFFFFF95h