Let's first make Global_EN understanding clear.
In CM4IO board design, the Global_EN is generated using a line driver 74LVC1G07SE-7 and nRTC_INT from a low power real time clock generator PCF85063A.
The nRTC_INT is active low output signal from low power real time clock generator PCF85063A. The signal nRTC_INT is normally high all the time in normal operation but in case of alarm, the nRTC_INT goes low which brings Global_EN low for a while that reset CM4, is that correct ?
The Global_EN has to be low for more then 1ms to reset CM4.
Th circuit generating Global_EN in CM4IO board is attached.
In my application I am not using real time clock generator PCF85063A. I have connected/pulled high Global_EN to +5V through a 1k ohm resistor. The Global_EN is also connected to a capacitor and a reset switch. I have attached the circuit showing how Global_EN is pulled up to +5V. In normal operation, the Global_EN will remain high that keeps the CM4 working normally. When the reset push button is presses, the Global_EN will go low for a while that reset the CM4. Would it work ?
In CM4IO board design, the Global_EN is generated using a line driver 74LVC1G07SE-7 and nRTC_INT from a low power real time clock generator PCF85063A.
The nRTC_INT is active low output signal from low power real time clock generator PCF85063A. The signal nRTC_INT is normally high all the time in normal operation but in case of alarm, the nRTC_INT goes low which brings Global_EN low for a while that reset CM4, is that correct ?
The Global_EN has to be low for more then 1ms to reset CM4.
Th circuit generating Global_EN in CM4IO board is attached.
In my application I am not using real time clock generator PCF85063A. I have connected/pulled high Global_EN to +5V through a 1k ohm resistor. The Global_EN is also connected to a capacitor and a reset switch. I have attached the circuit showing how Global_EN is pulled up to +5V. In normal operation, the Global_EN will remain high that keeps the CM4 working normally. When the reset push button is presses, the Global_EN will go low for a while that reset the CM4. Would it work ?
Statistics: Posted by TommyBills — Wed Jun 25, 2025 6:06 am