Is Displacement mode and base register mode both are same??
Yes, both ae same.
Base-register addressing is a type of Displacement mode .
Displacement Mode = Register direct Mode + Register indirect addressing mode
example : in Displacement addressing we calculate Effective Address as EA = A + (R)
like Add R4, 100(R1) means R4 <- R4 + M[100+R1] // here displacement is 100 . We add 100 with register R1 value and get the memory address that is M[100+R1] , then get that value store in memory address and add that value with R4 . And finally store that addition into R4 .
Base-Register Addressing:The reference register contains a memory address, and the address field contains a displacement from that address. The register reference may be explicit or implicit.
MOV AL,[BX+7] // here BX is a base register and displacement is 7
// suppose the register BX contain 0103.The offset will be 0103+7=0110. Content of the memory location 0110 will move to AL.
so it is same as displacement addressing mode.