Unfortunately it is a fixed divide-by-four, so the module frequency is strictly coupled to the system clock. ________________________________________ From: Saxena, Anshuman [[email protected]] Sent: Wednesday, July 21, 2010 6:55 PM To: Paul Stuart; '[email protected]' Subject: Re: Dm355-270 SD/MMC Module Freq
Hi, If I remember correctly, there is an internal divider in the MMC/SD module which can control the clock going into the module. I have to double check though. We had used DM355-270 version and had it working with slower SD cards at 25-30 MHz clock also. So I assume your use case should be covered. Regards, Anshuman ----- Original Message ----- From: davinci-linux-open-source-bounces+anshuman=ti....@linux.davincidsp.com <davinci-linux-open-source-bounces+anshuman=ti....@linux.davincidsp.com> To: [email protected] <[email protected]> Sent: Thu Jul 22 03:22:37 2010 Subject: Dm355-270 SD/MMC Module Freq Hi There, Does anyone know if the DM355-270 can run at full speed and have reliable SD/MMC module behavior? We are using the 270 MHz variety of the DM355, clocked up to 270MHz. Now, the SD/MMC module claims that it only supports a module clock speed up to 100MHz, but running at 270 MHz produces a module's clock of 135 MHz. Since the sysclk2 divider is a fixed, to even get close to spec (108MHz) one would need to clock the ARM down to 216MHz... and start asking why we paid more for the 270 MHz part :) I see mostly good behavior on SDHC cards when we are over clocking the module at 135MHz, but get cards every now and again that throw buffer IO errors on data read timeouts. Anyone vouch for 135 MHz module clock working with a variety of SDHC cards? Thanks, Paul _______________________________________________ Davinci-linux-open-source mailing list [email protected] http://linux.davincidsp.com/mailman/listinfo/davinci-linux-open-source _______________________________________________ Davinci-linux-open-source mailing list [email protected] http://linux.davincidsp.com/mailman/listinfo/davinci-linux-open-source
