ICSP based programmer works only with 16F628 and nt 16F877 ?

[arunb]

Hi,

I have managed to make an ICSP based programmer for 16F628, 16F877, 16F628A and 16F877A mcus. I find that the programmer is able to program (High Voltage programming only), read only the 16F628 mcu, whereas it does not program the 16F877/16F877A, nor am i abe to read it correctly..

I sending the correct signals to the MCLR, PGC, PGD pins. These I have checked with a scope.

Please advise if the programming sequence of the 16F628 is the same as for the 16F877/16F877A mcus ?? Or is there any other mistake i am making??

Note: I also used a a 16F648A mcu and found that this did not work as well..

I could post the code if required??

thanks
arunb

[Ttelmah]

On the 628, you load one word, and then program. On the 877, you load eight words, and then program. Pull the respective programming data sheets, the flowchart will probably show what is wrong.

Best Wishes

[arunb]

Hi,

Thank you for the quick reply, I was not aware that the 16F877 required 8 words at a time, is the programming methods different for each of the 16F628 Ics ??

Please also send me the link (or article number) for the programming specifications of the 16F877 Ics.

thanks
arunb

[Ttelmah]

39025F for the 877
39589b f the 877A
The 'eight cycle' change, was for the A.
Generally, there are small changes (timings, number of cycles etc.), for every chip model.

Best Wishes