On Wed, 24 Aug 2005, Philip Rowlands wrote: >Who wrote this comment: > * Progfou: specification says to send config data before > * frequency in case (wanted frequency < current frequency). >and does it still apply to the MK3s? (Rhetorical, I don't expect >ivtv-devel to necessarily know.)
Some more facts gleaned from the web: The Philips FMI1216MK2 (and presumably others) have a nearly-compatible i2c format to the more recent tuners. There are examples given in the datasheet for programming in various byte orders: TELEGRAM EXAMPLES (WRITE MODE) Start - Adb - Ack - Db1 - Ack - Db2 - Ack - Cb - Ack - Pb - Ack - Stop. Start - Adb - Ack - Cb - Ack - Pb - Ack - Db1 - Ack - Db2 - Ack - Stop. Start - Adb - Ack - Db1 - Ack - Db2 - Ack - Cb - Ack - Stop. Start - Adb - Ack - Db1 - Ack - Db2 - Ack - Stop. I'd bet $5 that the MK3 tries to remain compatible with existing software/controllers, but in an undocumented fashion. Perhaps Philips has also worked around some limitations; here's a section which does not appear in the MK3 spec, and explains the byte switching: Remark: for channel selection involving band switching, and to ensure smooth tuning to the desired channel without causing unnecessary charge pump action, it is recommended to consider the difference between wanted channel frequency (fw) and the current channel frequency (fc): - If fw > fc, use telegram as: Start - Adb - Ack - Db1 - Ack - Db2 - Ack - Cb - Ack - Pb - Ack - Stop. - If fw < fc, use telegram as: Start - Adb - Ack - Cb - Ack - Pb - Ack - Db1 - Ack - Db2 - Ack - Stop. Unnecessary charge pump action will result in very low tuning voltage (VT ~= 0 V) which may drive the oscillator to extreme conditions. So going up, it wants to set the frequency before the band, and the opposite when going down. If I knew what "unnecessary charge pump action" is, this might make sense :) Cheers, Phil ------------------------------------------------------- SF.Net email is Sponsored by the Better Software Conference & EXPO September 19-22, 2005 * San Francisco, CA * Development Lifecycle Practices Agile & Plan-Driven Development * Managing Projects & Teams * Testing & QA Security * Process Improvement & Measurement * http://www.sqe.com/bsce5sf _______________________________________________ ivtv-devel mailing list ivtv-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/ivtv-devel
