Pull PGM to GND and assorted uC questions!

Hello everyone, I'm fairly new to the forum but I have read the Newcomers Sticky!

I have a couple of general questions so if anyone has the time to help iron out the kinks in my understanding I'd be very thankful:

1. PICs: I bought a JDM(2) programmer to ease my start in PICs along with a couple 16F628A and a handful of 16c63A (OTP). I managed to use WinPicProg (Nigel Goodwin) to burn hex files on to a 16F628A but I am confused about what "Pull PGM to Gnd" means in this case... I ask because when I try the same code with the same settings for IC-PROG the programmer returns jibberish when I verify the code. I know that it means to physically connect the PGM pin to the common ground rail through a resistor but how do I do this for a JDM programmer? OR, is this kind of instruction on of use when I try to perform ICSP? I need to iron out this kind of knowledge so that I dont waste the OTP 16c63s through silly mistakes when I get to them!

2. PICs: Configuration - why is it that every PIC seems to have a different set of configuration bits? The difference between a 628 and a 628A seems, to a newbie at least, quite big for a simple h/w revision.

3. 8051s: I have 2 chips; 1x 89s52 and 1x 89c52. As I understand it (?) the "s" type can be programmed using a simple "STK-like" programmer via ICSP. The "c" types however need a standalone programmer which is equipped with support chips... for which a preprogrammed "s" type could be used... I'm sure you can see where I going with this. Is this correct so far? If so could anyone personally recommend a "s" type programmer (schematic) that they consider good?

Thanks for you help

Palmiro said:

1. PICs: I bought a JDM(2) programmer to ease my start in PICs along with a couple 16F628A and a handful of 16c63A (OTP). I managed to use WinPicProg (Nigel Goodwin) to burn hex files on to a 16F628A

Click to expand...

I know Nigel will be supporting the JDM somedays.

But Palmiro, I doubted very much of what you have just said. Either the programmer is not of a JDM design or the software you are using is WinPic and not WinPicPro. You have to clarify that first.

Palmiro said:

but I am confused about what "Pull PGM to Gnd" means in this case...

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It means physically connect a resistor between the PIC PGM pin(628A pin10) and Vss. As it is done on the chip, it has nothing to do with the programming software setting or the JDM programmer itself.

Palmiro said:

2. PICs: Configuration - why is it that every PIC seems to have a different set of configuration bits? The difference between a 628 and a 628A seems, to a newbie at least, quite big for a simple h/w revision.

Click to expand...

Configuration bits let you determine how the PIC and some part of it should operate, which cannot/should not be altered during program running. For example, like the MCU operating speed, internal clock source or external, or code protection etc...It just like how you would make use of the space inside a new house. The bigger the house, the more you have to plan ahead and taking care of.

eblc1388, thank you for your response and, yes, sorry for the confusion, that's my fault:

I used Nigel's tutorials to get started but couldn't get his WinPicProg to work with my JDM programmer hence why I tried some others - these being WinPic (aka DL4YHF's PIC Programmer for Windows) and IC-Prog. I happened across WinPic from a suggestion on this board and then downloaded IC-Prog because it has the 16c63 chips listed as compatible targets which WinPic doesn't. But, as I tried to say, if I can't get the simpler 16F628A to burn then I can't risk the 16c63s until I understand more/why.

Re Pull PGM to Gnd: Right, let me see if I understand you: I have to physically attach a resistor between the two named pins on the chip itself? The thing I don't understand is that if this needs to be done for 16f628A chips why does everything go well anyway (ie without PGM to GND) when using JDM/WinPic but not IC-Prog? I notice that I can write to the chip using WinPic and then successfully READ it using IC-Prog but if I write using IC-Prog it will report verify failure and WinPic will then confirm that nothing or 'nonsense' has been written.

Also, why do some PICs need PGM to GND but not others?

At the end of the day I'm trying to get going so that I can build one of the better devices such as the PicStart+ or ICD2 clones in order to move forward.

Hi,
i can suggest you this JDM programmer that works with icprog. i use this programmer and it works very good.
https://amindzo.250free.com/pic-pg1a.pdf

Palmiro said:

Also, why do some PICs need PGM to GND but not others?

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The PGM pin is the low voltage programming input if the configuration bit is set. As you're not using LVP, that configuration bit should equal 0 (OFF) and the PGM input should not matter. A resistor between PGM and GND is used for prudence.
I serioulsy doubt that the PIC16C63 supports LVP, did you check the pin-out and find any pin with the PGM function?

amindzo,

thank you for the suggest - I inspected the schematic and it looks essentially the same as the one i have at the moment.

eng1,

It looks like I've made a twit of myself! I for some inexplicable reason thought that a JDM programmer was a LVP programmer which, had I even a glanced at the JDM page, I would have realised is quite wrong.

And you're correct with the 16c63 - it doesn't have a PGM pin so can't be LVP programmed - but since we've reasoned that my JDM doesn't do LVP anyway that's sort of academic!

Palmiro said:

I used Nigel's tutorials to get started but couldn't get his WinPicProg to work with my JDM programmer

Click to expand...

You won't, WinPicprog ONLY supports parallel port programmers, I don't consider 'serial port' programmers like the JDM reliable enough to support, so purposely never added a serial port option.

Did I happen to mention my illiteracy issues?! :-0