imx6ul soft reset

[yangguichuan]

Hello, when I applied the software reset function of IMx6UL, I set SRC_SCR register to 1, and found that it must enable the watchdog to work. I want to know the principle of this software reset.Is it to reset the chip directly or stop feeding the dog to reset the watchdog by stopping the internal code running?

[jimmychan]

SRC_SCR is used to control the resets on the chip. Please read the Reference Manual Chapter 49.7.1 for the meaning of the settings in this register. 

Please download the Reference Manual from here:

i.MX 6UltraLite Applications Processor Reference Manual 

https://www.nxp.com/products/processors-and-microcontrollers/arm-processors/i-mx-applications-proces...

[yangguichuan]

The 21, 17 and 13 bits of SRC_SCR register are all software reset. Is there any difference between them? There are no further details in the manual.

[yangguichuan]

But if I don't enable the watchdog and just set the 21st bit of the SRC_SCR register alone, it won't reset successfully. Only when the watchdog is enabled and the 21 bit of SRC_SCR register is set, will the reset be successful. Since it is a direct reset chip, may I ask why there is associated with the phenomenon that watchdog can only work?