OMAP-L138: Software Reset In SYSBIOS

Hello Peter,

You could perform a watchdog reset to trigger a Power-On Reset (POR). This will reset all internal logic (including emulation logic and the PLL logic) and clear internal memory.

For more information on POR, refer to section 6.4.1 of the datasheet: http://www.ti.com/lit/ds/symlink/omap-l138.pdf#page=84

For more information on using the watchdog timer mode, refer to section 31.1.6 of the TRM: http://www.ti.com/lit/ug/spruh77c/spruh77c.pdf#page=1498

After a POR, the following steps will occur:

1. The boot pins will be latched.
2. The DSP will come out of reset and begin execution of the DSP ROM bootloader.
   1. The DSP ROM bootloader will indirectly write the ARM reset vectors. Since the DSP does not have write access to the ARM local RAM, the PRU is used to perform this task
   2. The DSP takes the ARM out of reset and powers down
3. The ARM begins execution of the ARM ROM bootloader
   1. The ARM ROM bootloader will read from the boot medium and begin sequentially executing the AIS commands in the boot image.
   2. The last AIS command will jump to the entry point of the ARM executable.

After the boot process, the DSP will be powered down in reset until taken out of reset by the ARM.

I couldn't find any watchdog examples for OMAPL138, but I was able to find one for L137 that may be useful to look at:

Otherwise, you could do a warm reset, using HW, which will retain internal memory, and the boot pins will be not be latched and retain the same values from the last POR. Refer to the replies by Mark and Mukul in this thread: 

Regards,
Sahin