Thanks for your response and happy new year!
--On den 31 december 2002 10:43 +0100 Holger Waechtler <[EMAIL PROTECTED]> wrote:
Question 1: The module is supposed to get 9V and 32V, it gets 8.75V and 28.85V on those pins. How critical are those voltages?These tolerances should be specified in the datasheet, not? Usually they are only about a few volts for the PLL charge pump voltage and a few 10th volts for all lower voltages.
Certainly, sadly I haven't found any real datasheets on the web, only those two brief descriptions (and another version similar to the korean one at alps.co.uk), neither of which tells you very much about how to use the darn thing. I guess I should try calling them and ask for datasheets.
maybe you can improve things by playing with PLL and AGC register settings.
As for AGC-registers - I guess that should be in the SP8870? I found one document that describes some registers, but far from everything you would like to know, and not even all that is needed to get it going on a TT-DVB-T (especially the mystery 0301 register). If anyone has more information on it than the sp8870c-ch-ds.pdf Rev 1.1/9903 I'd be happy if you could share it with me. I have some more problems with it, it hangs (or probably just screws up its settings so it has to be cleaned up) every now and then when retuning. I followed you advice and finally came to playing with cranking up the charge pump current, which did a huge improvement. I changed the charge from 0 to 3 (120uA to 1200uA), which gave me pretty a nice and clean reception for the first time! Setting it to 2 (555uA) wasn't enough. I am not sure this is the right thing to do, and would really like some advice here (and/or the datasheet :-). Q1: Could it be harmful or otherwise bad to change it? Q2: What does this do anyway - up the PLL feedback loop BW? (Yeah, I should refresh my PLL knowledge, but asking experts is simpler and often gives interresting bonus information! :-) It is interresting to note that the TT windows driver seems to have the same problem and therefor presumably also sets the current to level 0. What is really the problem here anyway... I think one could also do some more work with the dividers than is currently done too have it retune faster and optimizing for being more stable, but since the SP8870 keeps screwing up on me it is hard to test it. Some advice from you tuner guys on how to proceed with this would be really good. Thanks for your help! /ragge PS. A note for anyone wanting to try this: You should also in sp5659_set_tv_freq change ...(pwr << 5)... into ...(pwr << 6)..., this must be a typo that newer has been a problem as pwr is 0. The same goes for alps_bsrv2.c. -- Info: To unsubscribe send a mail to [EMAIL PROTECTED] with "unsubscribe linux-dvb" as subject.
