Implementation of pipelining in datapath
- 1. PIPELINED DATA PATH MIPS Pipeline Instruction-execution classically takes 5 steps 1. Fetch 2. Decode 3. Execute 4. Memory Access 5. Write Back Fetch Instruction from Memory Decode the Instruction and Read Registers Execute the operation / Calculate an address Access an operand in Data Memory Write the result into a register
- 2. The Simple Data Path
- 3. IF ID EX MEM WB IF ID EX MEM WBInst 1 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 CLOCK CYCLES PROGRAMINSTRUCTIONS Instruction 1 Instruction 1 Instruction 1 Instruction 1 Instruction 1 EXECUTION WITHOUT PIPELINING SINGLE CYCLE IMPLEMENTATION
- 4. IF ID EX MEM WB IF ID EX MEM WBInst 1 Inst 2 IF ID EX MEM WB 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 CLOCK CYCLES PROGRAMINSTRUCTIONS Instruction 2 Instruction 2 Instruction 2 Instruction 2 Instruction 2 EXECUTION WITHOUT PIPELINING SINGLE CYCLE IMPLEMENTATION
- 5. IF ID EX MEM WB IF ID EX MEM WBInst 1 Inst 2 IF ID EX MEM WB Inst 3 IF ID EX MEM WB 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 CLOCK CYCLES PROGRAMINSTRUCTIONS Instruction 3 Instruction 3 Instruction 3 Instruction 3 Instruction 3 EXECUTION WITHOUT PIPELINING SINGLE CYCLE IMPLEMENTATION
- 6. IF ID EX MEM WB IF ID EX MEM WBlw $10,20($1) IF ID EX MEM WB IF ID EX MEM WB 1 2 3 4 5 6 7 8 9 CLOCK CYCLES PROGRAMINSTRUCTIONS Instruction 1 Instruction 1 Instruction 1 Instruction 1 Instruction 1 EXECUTION WITH PIPELINING IF ID EX MEM WB IF ID EX MEM WB Instruction 2 Instruction 2Instruction 3 Instruction 2Instruction 3Instruction 4 Instruction 2Instruction 3Instruction 4Instruction 5 sub $11,$2,$3 add $12,$3,$4 lw $13,24($1) add $14,$5,$6 Pipelining improves performance by increasing instruction throughput and decreasing the execution time of an individual instruction
- 7. IMPLEMENTATION OF PIPELINING A B C A B C Ed: log |x.y| A x.y, B ||, C log ()
- 8. Single Cycle Implementation of Data path
- 9. PIPELINED VERSION OF DATA PATH
- 12. EXECUTE
- 13. MEMORY ACCESS
- 14. WRITE BACK
- 15. IF ID EX MEM WB IF ID EX MEM WBlw $10,20($1) IF ID EX MEM WB IF ID EX MEM WB 1 2 3 4 5 6 7 8 9 CLOCK CYCLES PROGRAMINSTRUCTIONS Instruction 1 Instruction 1 Instruction 1 Instruction 1 Instruction 1 EXECUTION WITH PIPELINING IF ID EX MEM WB IF ID EX MEM WB Instruction 2 Instruction 2Instruction 3 Instruction 2Instruction 3Instruction 4 Instruction 2Instruction 3Instruction 4Instruction 5 sub $11,$2,$3 add $12,$3,$4 lw $13,24($1) add $14,$5,$6
- 16. THE SINGLE-CLOCK-CYCLE DIAGRAM CORRESPONDING TO CLOCK CYCLE 5 OF THE PIPELINE