Re: Internal 1-Wire bus question
Bryan Armstrong <bryan.armstrong-6tN4nzCoH/[email protected]>
| Newsgroups | gmane.comp.hardware.microcontrollers.tini |
|---|---|
| Message-ID | <[email protected]> |
Pavel Parkhomenko wrote: > I have a question about DSTINI1 schematics. I have searched archives, > but didn't find an answer. So, the question is: why DS2433 (U9) > is connected to non-buffered internal 1-Wire bus (INTOW), while DS2502 (U11) is > connected to buffered one (INTOWB)? Maybe the role of 2N7002 (Q4) > on INTOW is not to buffer this signal, but do to something else? The FET isolates the internal bus so that when the module is powered down, an external 1-Wire host can program the DS2502 (which requires 12V programming voltage) without frying the CPU through the port pin. -- -- Bryan Armstrong bryan.armstrong-6tN4nzCoH/[email protected] _______________________________________________ TINI mailing list TINI-6tN4nzCoH/[email protected] To UNSUBSCRIBE, edit your profile, or see list archives: http://lists.dalsemi.com/mailman/listinfo/tini