Homework No. 5 Design a MIPS processor that supports only the LW, SW, and BEQ instructions. Highlight the datapath for an SW instruction, showing the flow of data and the necessary y control signal values.

To design a MIPS processor that supports only the LW, SW, and BEQ instructions, we need to first understand the functionality of each instruction:<br /><br />1. LW (Load Word): This instruction loads a word from memory into a register. It uses the base register and an offset to calculate the memory address, and then loads the data stored at that address into the specified register.<br />2. SW (Store Word): This instruction stores a word from a register into memory. It uses the base register and an offset to calculate the memory address, and then stores the data from the specified register into that memory location.<br />3. BEQ (Branch if Equal): This instruction compares the values of two registers and branches to a new location in memory if they are equal. It uses the contents of the two registers to perform the comparison, and then updates the program counter based on the result.<br /><br />Now let's focus on the datapath for an SW instruction. The datapath is the set of components that process data in the processor. Here's a high-level overview of the datapath for an SW instruction:<br /><br />1. Instruction Fetch (IF): The IF stage fetches the instruction from memory and decodes it. In this case, the instruction is an SW instruction.<br />2. Register Fetch (RF): The RF stage retrieves the source register data from the register file.<br />3. Address Calculation (AC): The AC stage calculates the memory address where the data will be stored. It uses the base register and the offset value from the instruction to calculate the address.<br />4. Memory Access (MA): The MA stage accesses the memory at the calculated address and retrieves the data. Since we are performing a store operation, we need to write the data from the source register to memory.<br />5. Write Back (WB): The WB stage writes the data from the memory back to the destination register.<br /><br />Here are the necessary control signal values for the SW instruction:<br /><br />* IF: No control signals are needed in this stage.<br />* RF: No control signals are needed in this stage.<br />* AC: The control signal for the AC stage is the memory write enable signal (MWE), which is set to 1 to indicate that a memory write operation is taking place.<br />* MA: The control signal for the MA stage is also the memory write enable signal (MWE), which is set to 1 to indicate that a memory write operation is taking place.<br />* WB: No control signals are needed in this stage.<br /><br />In summary, the datapath for an SW instruction involves fetching the source register data, calculating the memory address, accessing the memory, and writing the data back to the destination register. The necessary control signal for the SW instruction is the memory write enable signal (MWE), which is set to 1 to indicate that a memory write operation is taking place.