Hello Gurus!

I have build a JDM programmer, and I am able to program 16F84 & 628 chips without problems.

But I could not program 877A. On the JDM programmer site, it tells JDM can program 877(A?), but cannot use the default schematic - I have to build an adapter.

http://www.jdm.homepage.dk/newpic.htm

It does not give detail about how to build the adapter (i.e. pin-mapping) for 877A, so I try to use its In-Circuit Serial Programig (ICSP) function.

http://www.jdm.homepage.dk/icsp.htm

Following the instruction, I linked the 5 pins (MCLR,Vdd,Vss,RB6,RB7) to the 877A, but it didn't work. I got "Verify failed ar address 0x00000", normaly it means the write was unsuccessful.

I now have the following questions -

1) Have you programed 877A using JDM and/or ICSP? How do you do it?

2) How (where) should I connect the other pins of 877A (i.e. ground, 5V, clock, etc)? I ONLY connect these 5 pins to the programmer, other pins is not connected to anywhere, but I suspect I could be wrong.

3) Where can I find information about how to build JDM/16F877A adapter?

Thank you very much!!!
Michael

 

Does the software you use explicitly say it supports 877A? Because pic 16F877 and 16F877A require diffirent programming routines.

16F877 is EEPROM, 16F877A is Flash

 

Exo, I mean no disrespect, but FLASH is another word for EEPROM

 

nope it isn't

Eeprom allows writing to a single word. Flash requires read/write in Blocks (i believe pics do it in blocks of 4 words)

(http://www.webopedia.com/TERM/F/flash_memory.html)

Anyway 16F877 and 16F877A require diffirent programming routine. You can not program a 16F877A with software that only supports 16F877

 

I used icprog on windows 2000. As I said, it can program 16F84A, which I assume to be similar to 16F877A regarding to programming algorithm/method.

icprog says it can program 877A, but I am not sure about JDM the hardware.

Also I wonder how should I connect the all 40 pins of 16F877A when program with JDM.

Regards.
Michael

 

Ok, i phrased it wrong, basically they say that flash is eeprom (which if what i meant)

but yeah, regardless of names, if programming technique is different then it's a no go

 

download the most recent version of IC-prog. It should support it. (Well mine does)

and you also need to add a capacitor of 100nf across VDD and VSS. and also a 4.7k resistor on RB3/PGM to the ground rail. This should work fine.

__________________
www.winpicprog.co.uk - Great PIC language tutorials.

 

To clear this up, the 16F84A is still an EEPROM chip, the first FLASH PIC chips appear to be the 16F877A series - the technology used is totally different, and they require programming differently. The new FLASH chips program much faster than the old EEPROM ones.

As the author of WinPicProg I've spent a fair bit of time sorting this all out, interestingly enough icprog includes the 16 bit version of my disassembler, presumably he based icprog on my old 16 bit code which I released?.

MicroChip (along with other manufacturers) have confused the issue greatly by calling the EEPROM chips FLASH - purely for advertising purposes.