<section begin="History" />

!colspan="4" style="width:100%; text-align:left"; border-bottom:solid 2px #ededed"|History

!style="border-left:solid 2px #73B2C7; border-right:solid 2px #73B2C7;border-top:solid 2px #73B2C7; border-bottom:solid 2px #73B2C7; background-color:#73B2C7; padding:5px; color:white"|Version!style="border-left:solid 2px #73B2C7; border-right:solid 2px #73B2C7;border-top:solid 2px #73B2C7; border-bottom:solid 2px #73B2C7; background-color:#73B2C7; padding:5px; color:white"|Issue Date!style="border-left:solid 2px #73B2C7; border-right:solid 2px #73B2C7;border-top:solid 2px #73B2C7; border-bottom:solid 2px #73B2C7; background-color:#73B2C7; padding:5px; color:white"|Notes

|style="border-left:solid 2px #73B2C7; border-right:solid 2px #73B2C7;border-top:solid 2px #73B2C7; border-bottom:solid 2px #73B2C7; background-color:#edf8fb; padding:5px; color:#000000"|X1.Y0.Z0|style="border-left:solid 2px #73B2C7; border-right:solid 2px #73B2C7;border-top:solid 2px #73B2C7; border-bottom:solid 2px #73B2C7; background-color:#edf8fb; padding:5px; color:#000000"|Month YearJan 2021|style="border-left:solid 2px #73B2C7; border-right:solid 2px #73B2C7;border-top:solid 2px #73B2C7; border-bottom:solid 2px #73B2C7; background-color:#edf8fb; padding:5px; color:#000000"|TBDFirst release

<section end="History" /><section begin="Body" />

Implementing correct power-up sequence for ''TBD: SOC 'iMX8MPlus'' processors is not a trivial task because several power rails are involved.

''TBDThe typical power-up sequence is the following: descrizione dei segnali che intervengono nella PS''# 3.3VIN main power supply rail is powered# SNVS domain signals are pulled-up (unless carrier board circuitry keeps this signal low for any reason)# CPU_PORn (active-low) is driven low by PMIC# RTC_RESET_B are internally released after 200ms# PMIC initiates power-up sequence needed by iMX8M processor# BOARD_PGOOD goes up when NVCC_3V3 (CPU I/O power rail) is ready# CPU_PORn is deasserted after the last regulator to bring the processor out of reset

''TBD: verificare le note sul BOARD_PGOOD''is generally used on carrier board to drive loads such as DC/DC enable inputs or switch on/off control signals.

Depending on the kind of such loads, BOARD_PGOOD is generally used on carrier board might not be able to drive loads such as DC/DC enable inputs or switch on/off control signalsthem properly because it has a 20mA output current absolute maximum rating.

Depending on the kind of such loads, BOARD_PGOOD might not be able to drive them properly. In these cases a simple 2-input AND port can be used to address this issue. The following picture depicts a principle schematic showing this solution.