How do we list the concrete RTN for load relative, “ldr”. A…

How do we list the concrete RTN for load relative, “ldr”. And The abstract RTN for ldr 2)How to  Add a new assembly instruciton to the SRC–an extra-strength add function. Here’s the abstract RTN: add (:= op=11) → R[ra] ← R[rb] + R[rc] + R[c3<11..7>] + R[c3<6..2>]

Answer

To list the concrete RTN for the load relative (“ldr”) instruction, we need to examine the opcode, operands, and the resulting operation. The ldr instruction is commonly used in assembly language programming to load a value from memory into a register using a relative address.

The concrete RTN (Register Transfer Notation) for the ldr instruction can be represented as follows:

RTN for ldr:
1. MAR <- PC + offset 2. MDR <- M[MAR] 3. R[rd] <- MDR In this RTN, MAR refers to the Memory Address Register, PC represents the Program Counter register, offset refers to the offset used to calculate the memory address, MDR denotes the Memory Data Register, and R[rd] represents the destination register where the loaded value will be stored. Now, let's move on to the abstract RTN for the "ldr" instruction. The abstract RTN provides a high-level representation of the operation without specifying the underlying hardware implementation details. Abstract RTN for ldr: 1. R[rd] ← M[MAR] (where MAR = R[ra] + R[rb] + R[c3<11..7>] + R[c3<6..2>])

In this abstract RTN, MAR represents the Memory Address Register, R[ra] and R[rb] are the source registers, R[rd] is the destination register, and R[c3<11..7>] and R[c3<6..2>] denote specific bit ranges of register R[c3].

Next, let’s discuss how to add a new assembly instruction called “extra-strength add” to the SRC (Simple RISC Computer) architecture. The abstract RTN for the extra-strength add function is already provided:

Abstract RTN for extra-strength add:
add (:= op=11) → R[ra] ← R[rb] + R[rc] + R[c3<11..7>] + R[c3<6..2>]

To add this new instruction to the SRC architecture, we need to consider the following steps:

1. Define the opcode value for the new instruction. In this case, it is “11”.
2. Modify the control unit of the SRC to recognize the new opcode and perform the corresponding operation.
3. Update the microarchitecture of the SRC to include the necessary hardware components to execute the extra-strength add instruction.
4. Implement the changes in the instruction set architecture (ISA) specification and documentation to reflect the addition of the new instruction.
5. Test the functionality of the extra-strength add instruction to ensure it operates correctly and does not interfere with the existing instructions in the SRC architecture.

By following these steps, we can successfully add the new extra-strength add instruction to the SRC architecture, expanding its capabilities to perform more complex arithmetic operations.