From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from smtp.sauce.co.nz ([210.48.49.72]) by www.linuxtv.org with esmtp (Exim 4.63) (envelope-from ) id 1KrGzT-0003bo-TR for linux-dvb@linuxtv.org; Sat, 18 Oct 2008 20:57:33 +0200 Message-ID: <48FA314B.5040203@clear.net.nz> Date: Sun, 19 Oct 2008 07:56:11 +1300 From: Richard Scobie MIME-Version: 1.0 To: Devin Heitmueller References: <412bdbff0810171104ob627994me2876504b43c18d8@mail.gmail.com> <2207.1224273353@kewl.org> <412bdbff0810171306n5f8768a2g48255db266d16aa8@mail.gmail.com> In-Reply-To: <412bdbff0810171306n5f8768a2g48255db266d16aa8@mail.gmail.com> Cc: linux-dvb Subject: Re: [linux-dvb] [RFC] SNR units in tuners List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: linux-dvb-bounces@linuxtv.org Errors-To: linux-dvb-bounces+mchehab=infradead.org@linuxtv.org List-ID: Devin Heitmueller wrote: > At this point the goal is to understand what the value means for > different demods. For the simple cases where the answer is "it's the > SNR in 0.1db as provided by register X", then it's easy. If it's "I > don't really know and I just guessed based on empirical testing, then > that is useful information too. According to the datasheet, the carrier to noise ratio for the BSRU6 front end, (which contains an stv0299), can be calculated in dB using the following information: Register ADD 24 NIRH 8 bits (MSB of noise indicator) Register ADD 25 NIRL 8 bits (LSB of noise indicator) C/N (dB) = -0.0017 * NIR + 19.02 Regards, Richard _______________________________________________ linux-dvb mailing list linux-dvb@linuxtv.org http://www.linuxtv.org/cgi-bin/mailman/listinfo/linux-dvb