Post by thread:[JunkMail] Re: [PIC:] Programming Specifications

At 06:36 AM 3/2/2004 -0500, you wrote: >On Tue, 2 Mar 2004, Tony Nixon wrote: > > > >And having an on-chip Vpp generator would be nice too. :) > > > > > > > > > > > Make 'em all LVP and do away with C series. :-) > >Unless you're like me, and never use LVP. I need the extra I/O pin. >Bill Or like me (and certain car companies) and distrust micros that can corrupt their own program memory. Best regards, Spehro Pefhany --"it's the network..." "The Journey is the reward" spam_OUTspeffTakeThisOuTinterlog.com Info for manufacturers: http://www.trexon.com Embedded software/hardware/analog Info for designers: http://www.speff.com -- http://www.piclist.com hint: PICList Posts must start with ONE topic: [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads

On Tue, Mar 02, 2004 at 08:45:02AM -0500, Spehro Pefhany wrote: > At 06:36 AM 3/2/2004 -0500, you wrote: > >On Tue, 2 Mar 2004, Tony Nixon wrote: > > > >> >And having an on-chip Vpp generator would be nice too. :) > >> > > >> > > >> > > >> Make 'em all LVP and do away with C series. :-) > > > >Unless you're like me, and never use LVP. I need the extra I/O pin. > >Bill > > Or like me (and certain car companies) and distrust micros that can > corrupt their own program memory. Are these (LVP, writing own program memory) not orthogonal? The 16F777 for example (to my surpise frankly) has LVP but cannot program its own memory. It was going to become my new 877 (because it has all the nanowatt stuff too) but that's gone by the wayside. I'm really looking for a 16F877A with nanowatt in it. As for LVP Bill is right. And it really sucks because the LVP pin is stuck right in the middle of an 8 bit port. I know why they did it: Only RB1-RB5 on the 16F74 that the family was modeled after did not have a secondary function attached and was available on both the 28 and 40 pin parts. It still sucks nevertheless. I wish that MChip could figure out a way to program that models Wouters ZPL bootloader which wiggles the MCLR in a particular pattern. Something simple like MLCR has to be low for a specific amount of time (like 1ms) to be considered a normal reset, but anything faster will actually count the time inbetween. Since nanowatt chips all have internal osciallators, it should be real simple to keep count of runtime since reset. But that's just wishful thinking. I'm on the ZPL train now and am actively working on a ZPL 16F implementation. Once I get that done I'll simply dedicate the 384 bytes to the chip for the bootloader, do a high voltage program (getting that RB4 back on the 16F87X chips), then wiggle MCLR to reprogram from then on. BAJ -- http://www.piclist.com hint: PICList Posts must start with ONE topic: [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads

At 06:16 PM 3/2/2004 -0500, you wrote: >Are these (LVP, writing own program memory) not orthogonal? To some extent, but the CONFIG switch disabling the internal charge pump makes things more secure. Not quite as good as a hardware write disable or leaving out the charge pump entirely, but it doesn't use up a pin, and I imagine the charge pump is shared with the EEPROM circuitry. Best regards, Spehro Pefhany --"it's the network..." "The Journey is the reward" .....speffKILLspam@spam@interlog.com Info for manufacturers: http://www.trexon.com Embedded software/hardware/analog Info for designers: http://www.speff.com -- http://www.piclist.com hint: PICList Posts must start with ONE topic: [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads

>>>>Make 'em all LVP and do away with C series. :-) >>>> >>>> >>>Unless you're like me, and never use LVP. I need the extra I/O pin. >>>Bill >>> >>> Surely they can make them all LVP only. Some new chips have VPP raised before VCC to enter programming mode. Holding RB6 and RB7 low, and then raising MCLR to 5V before applying VCC seems an easy way to accomplish this. I also can't see why the MCLR pin can't be used as the clock pin while in programming mode, and only need RB7 for the data pin. They could also expand on Wouters idea and just use MCLR, but perhaps synchronous clocking is easier to deal with. When not in programming mode, (VCC before VPP), MCLR works normally. regards Tony -- http://www.piclist.com hint: The list server can filter out subtopics (like ads or off topics) for you. See http://www.piclist.com/#topics