From mboxrd@z Thu Jan 1 00:00:00 1970 From: Nicolin Chen Subject: Re: Can iMX6SL supports different sampling rate for different SSIs? Date: Mon, 16 Mar 2015 17:38:30 -0700 Message-ID: <20150317003830.GA552@Asurada-GSX> References: <5507743B.5040808@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from mail-pa0-f41.google.com (mail-pa0-f41.google.com [209.85.220.41]) by alsa0.perex.cz (Postfix) with ESMTP id E46B92619FB for ; Tue, 17 Mar 2015 01:38:37 +0100 (CET) Received: by pacwe9 with SMTP id we9so80257336pac.1 for ; Mon, 16 Mar 2015 17:38:36 -0700 (PDT) Content-Disposition: inline In-Reply-To: <5507743B.5040808@gmail.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: alsa-devel-bounces@alsa-project.org Sender: alsa-devel-bounces@alsa-project.org To: Xuebing Wang Cc: alsa-devel@alsa-project.org, niranjan Patil , Richard Jiang List-Id: alsa-devel@alsa-project.org On Tue, Mar 17, 2015 at 08:24:27AM +0800, Xuebing Wang wrote: > 2) As pll4_main_clk is global for all 3 SSIs, I think that we can *not* use > 8k for ssi1 and 44.1k for ssi2, right? Because 8k and 44.1k requires > different pll4 clock, right? True. > -- However, as 48k, 32k, 16k, 8k can use same pll4, thus different SSI > can use different sampling rate in this subset (48k, 32k, 16k, 8k). > -- Same principle applies for 44.1k, 22.050, 11.025 subset of sampling > rates. Correct. You need to choose 48K-group or 44.1K-group if only using PLL4. If you are so obsessed with full sample rate support in hardware level, you might need to do a trade-off like sacrificing video function -- you would then be allowed to use PLL5 to forge a rate for another rate group. I forgot if PLL3, another possible parent clock of SSI, is suitable for one of the groups. You may also take a look at it. Nicolin