I'm not quite sure what you mean. A reference clock doesn't compute an offset, it acquires, formats and returns a time value from an external source. NTP takes care of the rest.
-----Original Message----- From: questions-bounces+gdowd=symmetricom....@lists.ntp.org [mailto:questions-bounces+gdowd=symmetricom....@lists.ntp.org] On Behalf Of Juergen Kosel Sent: Thursday, December 11, 2008 10:53 AM To: questions@lists.ntp.org Subject: [ntp:questions] how to write a reference clock driver Hello, I have a system with hardware support for PTP (IEEE 1588 time synchronisation) [ http://en.wikipedia.org/wiki/Precision_Time_Protocol ]. So the system can read from two 32 bit registers seconds and nanoseconds since 1.1.1970. It appears like the system time, but is n't the system time. To synchronize the system time to the PTP synchronized time and to provide it to other systems, I want to write a reference clock driver. I have already read http://www.eecis.udel.edu/~mills/ntp/html/howto.html and started with a copy of refclock_local.c. But from the documentation it is not clear, in what way the offset should be calculated and used. E.g.: offset = ref_clock_time - system_time; or offset = system_time - ref_clock_time; Greetings Juergen _______________________________________________ questions mailing list questions@lists.ntp.org https://lists.ntp.org/mailman/listinfo/questions _______________________________________________ questions mailing list questions@lists.ntp.org https://lists.ntp.org/mailman/listinfo/questions
