Q36,paper 3,d12. Suppose a processor does not have any stack pointer regist ers, which of the following statements is true ?

(A) It cannot have subroutine call instruction.

(B) It cannot have nested subroutine calls.

(C) Interrupts are not possible.

(D) All subroutine calls and interrupts are possible.

Answer (d)

calling convention is an implementation-level (low-level) scheme for how the subroutines  receive parameters from their caller and how they return a result. Differences in various implementations include where parameters, return values and return addresses are placed(registers or stack) and how the tasks of preparing for a function call and cleaning up the environment afterward are divided between the caller and the callee.