Post by thread:[PIC]: 18F eeprom programming algorithm

I have trouble programming the data eeprom of the 18F's (using my own programmer, not by a programming running on the PIC). Contrary to what p14/15 of the programming manual requires I can (only) get it to work when I replace the 'Hold SDATA low until write completes' with a real NOP (with clocking for the 16 'data' bits), followed by the wait. Any programmer-authors got care to comment? 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.

part 1 2205 bytes content-type:text/plain; (decoded 7bit) > I have trouble programming the data eeprom of the 18F's (using my own > programmer, not by a programming running on the PIC). Contrary to what > p14/15 of the programming manual requires I can (only) get it to work > when I replace the 'Hold SDATA low until write completes' with a real > NOP (with clocking for the 16 'data' bits), followed by the wait. Any > programmer-authors got care to comment? Hi, Wouter. I'm home right now and unfortunately my notes about programming the 18F EEPROM are at the office. However, I do have a copy of the source code here, which is attached. Take a look at the PICPRG_WRITE_18D routine. It's in Pascal, but I don't think you need to know the language details to follow the algorithm. This routine does work. Here is the salient snippet with error checking and other stuff deleted to make the algorithm more visible (see the attached file for the real thing): setsfr (pr, 16#A9, adr + ofs, stat); {set address to write to} setsfr (pr, 16#A8, dat[ofs] ! mr, stat); {write the data value to EEDATA} coreinst (pr, 16#84A6, stat); {BSF EECON1, WREN} setsfr (pr, 16#A7, 16#55, stat); {write 55h to EECON2} setsfr (pr, 16#A7, 16#AA, stat); {write AAh to EECON2} coreinst (pr, 16#82A6, stat); {BSF EECON1, WR ;start the write} coreinst (pr, 0, stat); {execute NOP instruction} picprg_cmdw_send (pr, 4, 0, stat); {do 4 clock cycles into another NOP} picprg_cmdw_wait (pr, 0.005, stat); {force 5mS wait before next operation} picprg_cmdw_send (pr, 16, 0, stat); {do remaining cycles of NOP} coreinst (pr, 16#94A6, stat); {BCF EECON1, WREN} There were various little errors and inconsitencies in every one of the programming specifications for the chips I implemented, but I don't remember off the top of my head exactly which issues applied to the 18F. I do remember that I had to take some educated guesses in a few places about how the thing really worked. I'll try to look up my notes when I get to the office. -- http://www.piclist.com hint: The PICList is archived three different ways. See http://www.piclist.com/#archives for details. part 2 22881 bytes content-type:application/octet-stream; (decode) part 3 2 bytes -

There was an errata about supplying ALL power pins, Vdd and AVdd, Vss and AVss with power. Andy At 11:09 PM 1/4/03 +0100, you wrote: {Quote hidden}>I have trouble programming the data eeprom of the 18F's (using my own >programmer, not by a programming running on the PIC). Contrary to what >p14/15 of the programming manual requires I can (only) get it to work >when I replace the 'Hold SDATA low until write completes' with a real >NOP (with clocking for the 16 'data' bits), followed by the wait. Any >programmer-authors got care to comment? > >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. -- http://www.piclist.com hint: The PICList is archived three different ways. See http://www.piclist.com/#archives for details.

> picprg_cmdw_send (pr, 16, 0, stat); {do remaining cycles of NOP} Thanx, that was my error: I overlooked that the 16 data bits must still be clocked in *after* the programming delay. For code and data I used a different piece of code anywway because the clock must remain high, so the problem appeared only for eeprom. Wouter van Ooijen -- ------------------------------------------- Van Ooijen Technische Informatica: http://www.voti.nl consultancy, development, PICmicro products -- http://www.piclist.com#nomail Going offline? Don't AutoReply us! email spam_OUTlistservTakeThisOuTmitvma.mit.edu with SET PICList DIGEST in the body

Wouter van Ooijen wrote: > I have trouble programming the data eeprom of the 18F's (using my own > programmer, not by a programming running on the PIC). Contrary to what > p14/15 of the programming manual requires I can (only) get it to work > when I replace the 'Hold SDATA low until write completes' with a real > NOP (with clocking for the 16 'data' bits), followed by the wait. Any > programmer-authors got care to comment? The pages you mentioned made me think you used the 'preliminary' DS39576A? Just yesterday I noticed there is a DS39576B which has among others a slightly different EEPROM programming instruction sequence (p16/17). Rob. -- Rob Hamerling, Vianen, NL phone +31-347-322822 homepage: http://www.robh.nl/ -- http://www.piclist.com#nomail Going offline? Don't AutoReply us! email .....listservKILLspam@spam@mitvma.mit.edu with SET PICList DIGEST in the body