I'm also working on this but have not succeeded to take the system to sleep yet. Could you please tell me if you just set the GIO000 to low to take it to sleep?
However regarding the other peripherals it looks like we have to disable the outputs of PSC entirely. Have you also cutdown the core-clock? The SPRUB3 mentions "To reduce the chip stand by power, it is advised to power down all the analog blocks (PLL cores, DDR PHY DLL, DDR PHY, USB PHY, Video DAC, and CCP PHY). " -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] p.com] On Behalf Of Jeff Cooper Sent: Thursday, September 11, 2008 8:39 PM To: davinci-linux-open-source@linux.davincidsp.com Subject: Deep sleep on the DM355 I'm trying to enable deep sleep on a DM355 and I'd like to know if anyone else has done that? I think that I've been able to enter and exit deep sleep mode successfully as I see the power draw on my system drop from 650 mW down to 190 mW when I'm in deep sleep. There's very little hard information on how much power the DM355 should draw in deep sleep mode. I've found a Power Point presentation on the net at: http://www.arrownac.com/manufacturers/texas-instruments/npi/products/dm3 55/davinci-dm355.ppt that states that the power consumption should be less that 5 mW while it's in deep sleep. I've also found a FAQ from TI that states that it should be approx 1 mW: http://focus.ti.com.cn/cn/lit/ml/sprv063a/sprv063a.pdf Assuming that the DM355 is in deep sleep mode and is really drawing around 5 mW, when I add in the maximum power draw from the other major components on my system, I'm still pretty far away from from what I'd expect the system to be drawing. The documentation in the Arm Subsystems User Guide (SPRUFB3) section 12.5.1 states: The transition of GIO0 from high to low creates a clock pulse advancing the Deep Sleep state machine. After this transition, all clocks are stopped and then the internal oscillators are powered down. I may be misunderstanding that statement, but I took it to mean that the system is in it's lowest power state at that point. I suspect that that may not be entirely true. I found that the VPSS oscillator, OTG analog block and USB PHY are still powered on. Turning those off saves about 12 mW. I suspect that other areas of the DM355 are still drawing power. Does anyone know of other areas of the chip that should be powered off separately prior to entering deep sleep? I've tried turning off the VPSS_Master and VPSS_Slave using the PSC controller, but that didn't have any noticeable effect. Does the PSC have any effect on power consumption when the system is in deep sleep mode? Does anyone know if the DSP side goes to sleep when you enter deep sleep? I've also noticed that the amount of power that the system consumes can very quite a bit between various deep sleeps. Using a software load that boots the kernel and puts the system to sleep, I've seen as much as 31 mW variance between boots once the system has entered deep sleep. I've yet to figure that one out. Any ideas on things to try or look into would be appreciated. thanks, Jeff -- Jeff Cooper // senior embedded software engineer LOGIC // engineering design services 411 Washington Ave. N. Suite 400 Minneapolis, MN 55401 T // 612.436.5176 F // 612.672.9489 [EMAIL PROTECTED] www.logicpd.com / / / / / / / / / / / / / / / / / / / / / / / / / / / / This message (including any attachments) contains confidential information intended for a specific individual and purpose, and is protected by law. If you are not the intended recipient, you should delete this message and are hereby notified that any disclosure, copying, distribution, or other use of this message, or the taking of any action based on it, is strictly prohibited. _______________________________________________ Davinci-linux-open-source mailing list Davinci-linux-open-source@linux.davincidsp.com http://linux.davincidsp.com/mailman/listinfo/davinci-linux-open-source DISCLAIMER: ----------------------------------------------------------------------------------------------------------------------- The contents of this e-mail and any attachment(s) are confidential and intended for the named recipient(s) only. It shall not attach any liability on the originator or HCL or its affiliates. Any views or opinions presented in this email are solely those of the author and may not necessarily reflect the opinions of HCL or its affiliates. Any form of reproduction, dissemination, copying, disclosure, modification, distribution and / or publication of this message without the prior written consent of the author of this e-mail is strictly prohibited. If you have received this email in error please delete it and notify the sender immediately. Before opening any mail and attachments please check them for viruses and defect. ----------------------------------------------------------------------------------------------------------------------- _______________________________________________ Davinci-linux-open-source mailing list Davinci-linux-open-source@linux.davincidsp.com http://linux.davincidsp.com/mailman/listinfo/davinci-linux-open-source
