Post by thread:[PIC]: Count processor cycles PIC16F84 problem

Hello PICLIST, I have one question which answer I can't find clearly in Microchip documentation. How much processor cycles get this instruction: addwf PCL,F ; W + PCL -> PCL In documentation is said that addwf take only 1 processor cycles but it change the PCL and in datasheet it said in this case it take 2 cycles. My question is anyone know how many cycles take this instruction addwf PCL,F ? -- Best regards, Ivan spam_OUTi_dachevTakeThisOuTprosyst.bg -- http://www.piclist.com hint: The PICList is archived three different ways. See http://www.piclist.com/#archives for details.

> My question is anyone know how many cycles take this instruction > addwf PCL,F ? 2 BTW writing the same value back to PCL should be interpreted as a modification, so it is 2 even when the value of W is 0. BTW2 this holds for ALL instructions that write to PCL! Wouter van Ooijen -- ------------------------------------------- Van Ooijen Technische Informatica: http://www.voti.nl consultancy, development, PICmicro products -- http://www.piclist.com hint: The PICList is archived three different ways. See http://www.piclist.com/#archives for details.

> How much processor cycles get this instruction: > > addwf PCL,F ; W + PCL -> PCL Takes 2 cycles (tried it with Stopwatch) -- http://www.piclist.com hint: The PICList is archived three different ways. See http://www.piclist.com/#archives for details.

Two Bob Ammerman RAm Systems ----- Original Message ----- From: "Ivan Dachev" <.....i_dachevKILLspam@spam@PROSYST.BG> To: <PICLISTKILLspamMITVMA.MIT.EDU> Sent: Monday, February 03, 2003 3:07 AM Subject: [PIC]: Count processor cycles PIC16F84 problem {Quote hidden}> Hello PICLIST, > > I have one question which answer I can't find clearly in > Microchip documentation. > > How much processor cycles get this instruction: > > addwf PCL,F ; W + PCL -> PCL > > > In documentation is said that addwf take only 1 processor cycles > but it change the PCL and in datasheet it said in this case it take > 2 cycles. > > My question is anyone know how many cycles take this instruction > addwf PCL,F ? > > > -- > Best regards, > Ivan .....i_dachevKILLspam.....prosyst.bg > > -- > http://www.piclist.com hint: The PICList is archived three different > ways. See http://www.piclist.com/#archives for details. > -- http://www.piclist.com hint: The PICList is archived three different ways. See http://www.piclist.com/#archives for details.

> How much processor cycles get this instruction: > > addwf PCL,F ; W + PCL -> PCL > > > In documentation is said that addwf take only 1 processor cycles > but it change the PCL and in datasheet it said in this case it take > 2 cycles. In general a ADDWF takes one cycle. However, whenever the PC is changed the prefetched instruction must be flushed, which wastes one cycle. Therefore, ADDWF to PCL takes two cycles, but ADDWF to anything else takes just one cycle. ***************************************************************** Embed Inc, embedded system specialists in Littleton Massachusetts (978) 742-9014, http://www.embedinc.com -- http://www.piclist.com hint: The PICList is archived three different ways. See http://www.piclist.com/#archives for details.