VSS & VDD on opposite sides

[Russlk]

I see that VDD and VSS are on opposite sides of the chip, 12F675 & 16F627A, so how does one programmer handle that? I am using Melabs USB programmer.

 

[Nigel Goodwin]

I see that VDD and VSS are on opposite sides of the chip, 12F675 & 16F627A, so how does one programmer handle that? I am using Melabs USB programmer.

If you look at the wiring of a P16PRO40, it's designed so you fit different size chips in different parts of the 40 pin ZIF socket, is your programmer the same?.

 

[Mike - K8LH]

Hi Russel,

The melabs USB and Serial programmers are ICSP programmers so you connect PGD, PGC, GND, VDD, and VPP directly to those pins on a target board...

If you get the melabs ZIF-40 adapter board you'll find they wire the board to be 'flipped' so that you program 28 and 40 pin devices one way and 8-pin through 20-pin devices the other way... Here's a modified version of the ZIF-40 board I use for my melabs Serial programmer and my Kit182 programmer that can be built using three 20-pin single-row machined sockets or a 40-pin ZIF socket...

Have fun... Regards, Mike

 

[Russlk]

Thanks for the info, Mike, but the VSS connection on 12F675 is pin 8. There is no connection to pin 8 on the target board, so how does that work?

 

[Mike - K8LH]

Thanks for the info, Mike, but the VSS connection on 12F675 is pin 8. There is no connection to pin 8 on the target board, so how does that work?

If you look closely, you'll see all of the VSS connections are on the red ground plane layer...

Kind regards, Mike

 

[Russlk]

OooK, I assume the 5 pin connector is for the Kit182 programmer?

 

[Mike - K8LH]

OooK, I assume the 5 pin connector is for the Kit182 programmer?

Yes...

 

[Mike - K8LH]

Here are some programming pinouts that I hope may help in your research...

Kind regards, Mike

 

[Russlk]

Great! Just what I needed, thanks.