资 源 简 介
Because the i.MX28 is a PMU and an SoC， power-on reset is generated internally and there is no TIming
requirement on external pins.
The i.MX28 can be reset by asserTIng the external pin RESETN for at least 100 mS and later deasserTIng
RESETN.
If the reset occurs while the device is only powered by the battery， then the reset kills all of the power
supplies and the system reboots on the asserTIon of PSWITCH. If auto-restart is set up ahead of time， the
system reboots immediately.
If the chip is powered by 5 V， then the reset serves to reset the digital sections of the chip. If the DCDC is
operating at the time of the reset， then power switches back to the default linear regulators powered by 5 V.
