Im really confused. Please show work and dont copy other answers. 1. A two-word

Question

Im really confused. Please show work and dont copy other answers.

1. A two-word instruction is stored at location 0x03C7 with its address field at location 0x03C8 (i.e. trailing word). The address field has a value of 0x8211. A processor register Rl contains the value 0x018A. Calculate the effective address (EA) if the addressing mode of the instruction is (a) direct; (b) immediate; (c) PC relative; (d) register indirect; (e) indexed with RI as the index register. Show your work and the 16-bit hexadecimal result of the EA calculation. indiect addressing mode

Explanation / Answer

Given that two-word instruction is stored at location 0x03C7 with its address field at 0x03C8.

Value of address field = 0x8211

Value of Register R1 = 0x018A

a)

In direct mode effective address of data is given in instruction.

Here, value of address field is 0x8211 which is effective address.

Therefore, Effective address = 0x8211

b) Immediate

In immediate addressing mode, operand is specified in instruction itself. So, operand will be 0x8211 and address of this operand is 0x03C8.

Therefore, effective address(EA) = 0x03C8

c) PC relative

In relative mode, value of address field is added to program counter to obtain effective address of operand.

Therefore, effective address = 0x03C9 + 0x8211

= 0x85D9

d) register indirect

In this mode of addressing, address of operand is placed in register.

So, effective value = 0x018A as value of register R1 is 0x018A

e) Indexed with R1 as index register

In absolute indexed addressing, content of address filed is added to content of index register to obtain effective address.

So, effective address = 0x8211 + 0x018A

= 0x839B

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