instruction execution

In serial execution, one would see
FDXFDXFDXFDXFDXFDX
but with pipelining, one sees
      FDX
       FDX
        FDX
         FDX
          FDX
           FDX

example

        LOAD  #40,A      ; load 40 in A
        MOVE  A,B        ; copy A in B
        ADD   #20,B      ; add 20 to B
        STORE B, 0x300   ; store B into memory cell 0x300
In serial form, this is executed as 
      Fetch LOAD
                Decode LOAD
                            Execute LOAD
                                        Fetch MOVE
                                                    Decode MOVE
                                                                Execute MOVE
                                                                            Fetch ADD
                                                                                        Decode ADD
                                                                                                    Execute ADD
                                                                                                                Fetch STORE
                                                                                                                            Decode STORE
                                                                                                                                        Execute STORE
but when pipelined, this is executed as 
      Fetch LOAD
                Decode LOAD
                          Execute LOAD
                Fetch MOVE
                          Decode MOVE
                                    Execute MOVE
                          Fetch ADD
                                    Decode ADD
                                              Execute ADD
                                    Fetch STORE
                                              Decode STORE
                                                        Execute STORE
pipelines.html was last edited by Randolph Bentson, on 2009/11/02T13:27:04-08:00