copado el simulador este para hacer pruebas con las 5 etapas de segmentación de MIPS. saludos Nico http://www.ecs.umass.edu/ece/koren/architecture/windlx/main.html Overview This application is a partial simulation of a MIPS Five Stage Pipeline. The user can pick from a limited number of assembly instructions to be executed in the pipeline. Instructions in the pipeline are checked for "possible" data and structural hazards before execution. During execution, the instructions can be stepped through the stages of the pipeline one cycle at a time, or the final results can be displayed instantly. The display shows where stalls have occurred in the pipeline. Data forwarding can be enabled or disabled. The simulation does not allow the user to insert specific values into the registers and does not compute the actual result of any of the instructions. This is simply a tool that should be used to detect possible data and structural hazards and to view instructions as they are executed on a five stage MIPS pipeline. Instructions are issued "in-order" so WAR hazards can never occur while the instructions are being executed. However, WAR hazards are listed under the "Potential Hazards" for completeness. It is assumed that there is a sperate data cache and instruction cache so that stalls will never occur due to an instruction being read from memory at the same time as a piece of data is being read from or written to memory. Registers The simulation supports 16 Floating-Point Registers (R1 - R16) and 32 Integer Registers (F1 - F32). Assembly Instructions The following assembly instructions are supported: FP_Add(dest, src1, src2) The floating-point add instruction adds the two source registers and stores the result in the destination register. This instruction can take from 1 - 20 cycles to complete execution. The execution time is selectable by the user and is always the same as the FP_Sub instruction. FP_Sub(dest, src1, src2) The floating-point subtract instruction subtracts the two source registers and stores the result in the destination register. This instruction can take from 1 - 20 cycles to complete execution. The execution time is selectable by the user and is always the same as the FP_Add instruction. FP_Mult(dest, src1, src2) The floating-point multiply instruction multiplies the two source registers and stores the result in the destination register. This instruction can take from 1 - 20 cycles to complete execution. The execution time is selectable by the user. FP_Div(dest, src1, src2) The floating-point divide instruction divides the two source registers and stores the result in the destination register. This instruction can take from 1 - 20 cycles to complete execution. The execution time is selectable by the user. FP_Load(dest, offset, src1) The floating-point load instruction uses an integer value stored in source register # 1 and an offset to compute the memory address from which data will be loaded into the destination register. This instruction takes 1 cycle during the execution stage to compute the memory address. The value from memory is available after the MEM stage. It is assumed that the requested data is always available in the data cache so that the pipeline will never have to stall while data is read from the memory. FP_Store(src1, offset, src2) The floating-point store instruction uses an integer value stored in source register # 2 and an offset to compute the memory address to which the data in source register # 1 will be stored. This instruction takes 1 cycle during the execution stage to compute the memory address. The value is written to memory by the end of the MEM stage. It is assumed that the data to be written to memory is already available in the data cache so that the pipeline will never have to stall while data is written to memory. This instruction does not go through the WB stage. INT_Add(dest, src1, src2) The integer add instruction adds the two source registers and stores the result in the destination register. This instruction takes 1 cycle to complete execution. INT_Sub(dest, src1, src2) The integer subtract instruction subtracts the two source registers and stores the result in the destination register. This instruction takes 1 cycle to complete execution. INT_Mult(dest, src1, src2) The integer multiply instruction multiplies the two source registers and stores the result in the destination register. This instruction takes 1 cycle to complete execution. INT_Div(dest, src1, src2) The integer divide instruction divides the two source registers and stores the result in the destination register. This instruction can take from 1 - 20 cycles to complete execution. The execution time is selectable by the user. INT_Load(dest, offset, src1) The integer load instruction uses an integer value stored in source register # 1 and an offset to compute the memory address from which data will be loaded into the destination register. This instruction takes 1 cycle during the execution stage to compute the memory address. The value from memory is available after the MEM stage. It is assumed that the requested data is always available in the data cache so that the pipeline will never have to stall while data is read from the memory. INT_Store(src1, offset, src2) The integer store instruction uses an integer value stored in source register # 2 and an offset to compute the memory address to which the data in source register # 1 will be stored. This instruction takes 1 cycle during the execution stage to compute the memory address. The value is written to memory by the end of the MEM stage. It is assumed that the data to be written to memory is already available in the data cache so that the pipeline will never have to stall while data is written to memory. This instruction does not go through the WB stage. BR_Taken(offset, src1) The branch taken instruction uses an integer value stored in source register #1 and an offset to compute the branch target memory address. This instruction assumes that the branch condition evaluates to "TRUE." Thus if there is an instruction immediately following this instruction in the pipeline, it must be canceled. It is assumed that the branch target address and the branch condition evaluation can be determined by the end if the ID stage. Thus this instruction never enters the EX stage. BR_Untaken(offset, src1) The branch untaken instruction uses an integer value stored in source register #1 and an offset to compute the branch target memory address. This instruction assumes that the branch condition evaluates to "FALSE." Thus if there is an instruction immediately following this instruction in the pipeline, it will continue to execute without any problems. It is assumed that the branch target address and the branch condition evaluation can be determined by the end if the ID stage. Thus this instruction never enters the EX stage. Structural Units This simulation contains 6 structural units that can cause a structural hazard. 1. Floating Point Add/Subtract Unit. 2. Floating Point Multiply Unit. 3. Floating Point Divide Unit. 4. Integer Add/Subtract Unit. 5. Integer Multiply Unit. 6. Integer Divide Unit. Note: The load and store instructions use the Integer Add/Subtract Unit to compute the memory address. Therefore, a floating-point load or store can be stalled by a floating-point add or subtract that takes longer than one cycle to complete. Using the Application The application loads into two frames. Initially, the bottom frame will be empty. Top Frame The top frame allows the user to enter and remove instructions from the pipeline. It also allows the user to set the execution time for several of the instructions and to enable or disable data forwarding. Adding an Instruction To add an instruction to the pipeline, the user first selects the name of the instruction they would like to add from the dropdown box. Once the name of the instruction has been selected, the user can select the registers they would like to associate with this instruction following the Assembly Instruction format. When the registers have been selected, the user should click the "Insert Instruction" button. This will cause the current state of the pipeline to appear in the bottom frame. The user can continue entering instructions repeating this procedure at any time. Removing an Instruction In the event that a user makes a mistake when entering an instruction into the pipeline, the last instruction can always be removed from the pipeline by clicking on the "Remove Instruction" button. Data Forwarding Data forwarding can be enabled by placing a checkmark in the "Data Forwarding" checkbox. Data forwarding can be disabled by removing the checkmark from the "Data Forwarding" checkbox. Whenever this value is changed, the bottom frame is updated to reflect the new state of the pipeline. Resetting the Application. The application can be reset at any time by clicking on the "Reset Application" button. Help This help page can be accessed at any time by clicking on the "Help" button. Setting the Instruction Execution Time There are 4 functional units for which the execution time can be modified by the user. To change the execution time for a particular functional unit, select the dropdown box next to the functional until and select the number of cycles that the functional unit should take to complete an operation. Whenever an execution time is changed, the bottom frame is updated to reflect the new state of the pipeline. Bottom Frame The bottom frame is divided into two sections. The upper section shows the instructions in the pipeline and what stage each instruction is in as it is executed. The lower section is used to list the potential structural and data hazards. Stepping Through the Instructions The user can step through the instructions in the pipeline one cycle at a time by clicking on the "Step" button repeatedly. Executing All Instructions The user can execute all instruction to completion in one step by clicking on the "Execute All Instructions" button.