Propeller Start-up

christopher

Hi,

I have just received 2 prop chips and I do not have the clip so I have tried the alternative circuits posted with no success. I have a 4Mhz xtal connected, reset at +3.3v and BOE at Gnd and no connection to host. On power -up after a while should I not see a pulse train on pins 38,37 as the chip searches for a 24lc256 eeprom based on the boot-up sequence. Or in the absence of a host connection what connections on RST and BOE that would allow me to see this sequence so that I can ascertain that the chip is still good!


Thanks

Chris

Trinidad W.I

cocokiwi

christopher said...
Hi,

I have just received 2 prop chips and I do not have the clip so I have tried the alternative circuits posted with no success. I have a 4Mhz xtal connected, reset at +3.3v and BOE at Gnd and no connection to host. On power -up after a while should I not see a pulse train on pins 38,37 as the chip searches for a 24lc256 eeprom based on the boot-up sequence. Or in the absence of a host connection what connections on RST and BOE that would allow me to see this sequence so that I can ascertain that the chip is still good!


Thanks

Chris

Trinidad W.I

···· Reset don,t goto·3.3v ...reset is pulsed by the· DTR drive transistor to ground or a push button,it may have a 10k internal pull up[noparse][[/noparse], a resistor is between reset and A29·maybe not used if one don't have

···· memory chip! if you have the reset @ 3.3v you maybe hanging it up!


·· cheers Dennis

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Post Edited (cocokiwi) : 5/10/2006 9:00:01 PM GMT

christopher

Thank you. Assuming I get the reset right should I see the pulse train in the absence of a host connection on P29,P28 ?


Chris

cgracey

Yes, you should see some activity on P29 (SDA)·and P28 (SCL). There may not be many pulses, though, since an EEPROM should respond somewhat on P29. Without that response, there may be only a few transitions before the Propeller decides there's nothing connected.

christopher said...
Thank you. Assuming I get the reset right should I see the pulse train in the absence of a host connection on P29,P28 ?


Chris

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Chip Gracey
Parallax, Inc.

christopher

Thank you. I got the chip up and running. I had an unreliable power supply.


Chris