The hexadecimal data 36AB4CFD4CA2 is located in the real mode memory within Little Endian format using a register indirect addressing mode. If the data index, DI, register contains the value 0004h and the data segment, DS, register contains the value 0001h. What will be the value stored into the 16-bit register, AX, after executing the mnemonic opcode operand instruction MOV AX, [DIJ? Use the figure below to solve this question. MOV AX, [DI] MEMORY Data Address EAX EDI DS OA AX register is loaded with the data AB36. OAX register is loaded with the data 36AB. Oc AX register is loaded with the data AB9A. Od. AX register is loaded with the data BA36.

:- We will be implementing a new instruction within the MIPS architecture. New instruction will decrement a Variable stored in a memory location and store the decremented value in a register (Rt). This new instruction will be called DECR. Its usage and interpretation is Usage: DECR Offset(4*Rs),Rt Interpretation: Reg[Rt]= Mem[4*Rs+Offset] - 1 Which blocks are used and which control signals are generated for this instruction. How would the Instruction code fields look like ? Do we need to add an extra hardware logic, explain ? (You may draw a simplified datapath flow)

Q3. If content of AX register is OXFEDC, BX is Ox9876 and CF = 1 respectively, !! Find contents of AX register if following instructions are executed on 8086 microprocessors SBB AX, BX (1) MUL BL (m) XOR AX, BX

(a) In MIPS machine language, the R format instructions need an additional field (the “funct” field) to specify the instruction type (“add”, “sub”, etc.). Why can’t this be done using just the 6-bit “op” field, which all MIPS instructions have, instead? (b) Give a sequence of MIPS assembly language instructions that adds the contents of $s0 and $s1, storing the result into $s0, if the contents of $s1 are greater than 6. Otherwise, the contents of $s0 should be incremented by 28. In either case, afterwards the contents of $s0 should be copied into $s2. (c) Suppose that the starting address of an array of words is stored in $s0. Give a MIPS assembly language instruction that loads the contents of the second word in the array into $s1. (d) Suppose that A and B are defined using “A: .word 0”, and “B: .space 100”. Give a sequence of MIPS assembly language instructions that calls a procedure “P” with its two arguments being the contents of A and the address of B, using the standard procedure…