We are running a survey to help us improve the experience for all of our members. If you see the survey appear, please take the time to tell us about your experience if you can.
Hi,
Setup: I am using C8051F124 MCU. I have configured UART0 for serial communication to acquire real time data.
Problem: When I do hardware reset (i.e. pulling down the RST pin on the MCU), the system halts and does not come up again. On the other hand when I do a power cycle with a pause of almost a sec, then the system restarts and is up and running again. Repeating the power cycle with the pause is of short duration, like about 200msec or lower the system again fails to come up.
Other Details: The system is running at 50MHz RSTSRC = 0x06 on initialization
Please help to identify the mistake I am doing.
Kind Regards, CM
if the source of last reset was a power-on or VDD monitor reset. But, it passed when there was a normal powercycle with more than 200msec duration between the voltage going down and coming up again. Here applies the law of unintended consequences. Someone got the not so brilliant idea to add a cap on the SILabs reset pin for 'noise suppression'. This, in effect, changes your reset from a Vdd monotor to a RC reset. I have thousand of units running with SILabs chips an no 'noise supprssion cap' they have none, zero, nada reset problems. just add a 4k7 or so from the reset pin to Vdd
Erik
Thanks mate.
Erik,
I appreciate your thoughts. I apparently do not have noise suppressant cap on the RST line of SILabs chip.
My RST line does have a 4k7 resistor to Vdd. I still saw this effect, hence the question.
Thanks
The reset chip I am using is MICREL 2776N. remove