Related to problem while programming the PIC18F4550

[milind.a.kulkarni]

Hi to All,

I was able to program PIC18F2550 from the PICkit-2 programmer but when I am putting PIC18F4550....In the 40 pin configuration mode of Programmer Could not able to identify the Device ID itself.....I tried also way out of force chip and selection of MCU family.....but still it way the same issue....Can any body face this issues and can any body guide me to solve this problem......Thanks in advance

 

[wp100]

Hi,

Other than memory size I am not aware there is any Programming difference between the two chips.

On the 4550 you have 2 VDD and 2 VSS pins - have you connected them all to the PK2 ?


I program both the 2550 and 4550 with the Pk2 ok.

 

[milind.a.kulkarni]

Yes .....I ...even tested two of PIC18F4550 but getting same problem......

 

[wp100]

Hi,


If all VDD and VSS are connected along with mcle, pclk and pdata as with the 2550 then the only other thing likely to be causing it is the path from the PK2 to your chip.

If the lead from the pk2 outlet is longer than 6" /150mm, unshielded , then sometimes some chips simply do not work when others do ...?

Do you have the chips in a breadboard or ic socket or Zif - again you could have a poor connection only showing up on the 40 pin chip.
Breadboard connectors are again not the best thing for high speed programming connections.

Have you tried running the PK2 diagnostics on both chips to see if they give the same results ?