Power Management CCS project for OMAP35x and AM-DM37x

Downloads

1. Download and unzip PowerManagement CCS project.
2. Downlaod the appropriate GEL files for your processor from the OMAP and Sitara CCS support page
3. Downlaod the appropriate CCS configuration file for your JTAG pod from the OMAP and Sitara CCS support page.

Project Description

This Code Composer Studio (CCS) project demonstrates entry and wakeup from OFF mode on and OMAP3EVM with either OMAP35x and AM/DM37x.

Setup

• Device : OMAP3530 ES3.1 or later, or AM/DM37x ES1.0 or later
• Board  : OMAP3EVM REV.G. One modification that needs to be made to the Power module. See diagram below.
• JTAG Emulator : Blackhawk USB560m, Ashling Opella-XDS560, Spectrum Digital XDS510USB
• CCS: We have used CCS 3.3 for this demonstration. The project could also be used in later CCS revisions.

Procedure

1. Unzip project and ensure CCS is setup to use the provided GEL files and CCS configuration file provided in the link above. The main GEL file is omap3530_cortexA.gel (or am-dm37x_cortexA.gel for AM/DM37x), which loads all the other GEL files (this is what you specify as the Cortex-A8 GEL file in CCS setup). You may need to adjust the path names in this file so this GEL can find the other GELs.
2. Open CCS and load up the following project: projects/pwr_mgt/pwr_mgt_idle_wkup_OMAP35xEVM/pjt/pwr_mgt_idle_wkup_OMAP35xEVM.pjt
3. You can build this project if you want, but it is already pre-built.
4. Power cycle the EVM and connect to the device from CCS (Debug -> Connect)
5. For OMAP35x, run GEL->OMAP3EVM->OMAP3EVMStart. For AM/DM37x, run GEL->OMAP3EVM->OMAP3730_EVMStart_with_Hynix
6. File->Load Program to load pwr_mgt_idle_wkup_OMAP35xEVM (it is found in the projects/pwr_mgt/pwr_mgt_idle_wkup_OMAP35xEVM/bin directory).
7. Because of the differences in how each JTAG pod handles low power, there are different procedures to run your code depending on the JTAG pod you have
   1. If you have a Spectrum Digital JTAG pod, this pod does not allow the processor to go into OFF mode while connected. Thus, in order to run the code, choose Debug -> Disconnect. Upon disconnect, the code will run, and after a few seconds, you should see the processor go into off mode for about 5 seconds. You can monitor this by probing VDD1 (J6) and VDD2 (J5) on the EVM and see them go to 0V. After about 5 sec, power is restored.
   2. If you have a Blackhawk JTAG pod, this pod seems to handle low power modes better. Choose Debug->Run. You will see some messages on the CCS console as the program is running. Then you will eventually get an CCS error because power was shut off to the processor. During this time (about 5 sec), you can probe VDD1 (J6) and VDD2 (J5) and see them go to 0V. After about 5 sec, power is restored. Click through the error messages that pop up due to a loss of power.
8. After power is restored, the device has come back from off mode, run Debug->Connect to restore connection to the device.
9. After connection, device should be sitting at a halt loop just after the WFI instruction, showing that we have successfully gotten back to a running state. DDR contents was also retained.

Resource

1. OMAP35x Debug Steps for Idle Entry
2. Optimizing OMAP35x OFF mode PAD configuration
3. Linux low power standby image
4. Tools For Debugging JTAG and Power Issues on DaVinci and OMAP devices(sprp603.pdf)