Pins for OEM

StarMan

I have read a post concerning this subject but I can't seem to find it.

I am designing a circuit board that will use a BS2 interpreter chip, eeprom and resonator.· There will be no serial communications.· I plan to use the DIP OEM components and program the eeproms on a BS2 OEM board and then plug them into the socket on my board.

My first question is - Do I tie the unused pins to Vdd, Vss, or nothing?

My second question is to Parallax - Why is there no SO package interpreter chip available?· I see one referenced in the BS2 OEM documentation but not on the website.· I would like to use surface mount components but I don't feel comfortable soldering the SS package.

Thanks,

Chris I.

Chris Savage

Chris,

·· Regarding the connections of unused pins, please see the schematic.· As for the surface mount parts, if you're not comfortable soldering them, I am curious how you plan to use them?


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Chris Savage
Parallax Tech Support
csavage@parallax.com

StarMan

Hi Chris,

Let me clarify my question.· If I remove the serial communications components from the schematic, pins 8, 9, and 28 will not have connections.· Do I pull these up, pull them down, or leave them as is?

I feel comfortable soldering an SO package with a larger pitch than the SS package.· My intent is to·save room taken up by the DIP package and to reduce board cost by eliminating holes.· I am using the freeware version of Eagle PCB and the board size is limited.

Thanks for your response.



Chris I.

Chris Savage

Chris,

·· I understand what you're saying, I guess I should've been a little more clear myself, I apologize.· The information is actually, for the most part in the schematic.· For example, one of the lines you refer to is the reset line (/MCLR), which needs to be pulled high through a 10K resistor.

·· Also, referring to the schematic it would suggest that RA3 would be pulled high through a 10K resistor as well.· And so should RA2.


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Chris Savage
Parallax Tech Support
csavage@parallax.com

dandreae

StarMan said...

My second question is to Parallax - Why is there no SO package interpreter chip available?· I see one referenced in the BS2 OEM documentation but not on the website.· I would like to use surface mount components but I don't feel comfortable soldering the SS package.

Thanks,

Chris I.

The reason that we don't offer the BS2 interpreter in a SO package is that we don't have a board·that uses it.· We use to carry the interpreter chip a long time ago in SO package·and now there hasn't been a demand for it lately.· However, we do offer the SS and dip form.

Dave

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Dave Andreae

Tech Support
dandreae@parallax.com
Http://www.parallax.com

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StarMan

Thanks Chris and Dave.