LOCKUP reset ( USB )

[CCandido]

Hi,

project example usb for MKS22.

Reset or  HardFault_Handler ( LOCKUP bit ).

my board power usb = 3.3v, cap-47uF, cap-100k, usb_cable short.

my test:

pullup resistor on RESET_PIN = 10K, 4K7, 1K, 100r ( ERROR).

else:

pullup resistor on RESET_PIN = 27R = ( ok )

exites other solution ?

thanks,

Carlos.

[jingpan]

Hi，

"The RESET_b pin, if enabled, must have a 100 nF capacitor close to the MCU for transient protection. The NMI_b pin, if enabled, must not have any capacitance connected to it. Each pin, when enabled as their default function, has a weak internal pullup, but an external 4.7 kΩ to 10 kΩ pullup is recommended. As with power pin filtering, it is recommended to minimize the ground loop for the capacitor and the VDD loop for the pullup resistor for these pins.
The RESET_b pin also has a configurable digital filter to reject potential noise on this input after power-up. The configuration bits are located in the RCM_RPFC register. While use of this filter may negate the need for the pullup and capacitor mentioned above, it is still recommended to use external filtering in electrically noisy environments."

Other hardware and software setting details please find in KQRUG.pdf with can be found in www.nxp.com.

Regards,

Jing

[CCandido · Accepted solution]

Hi Jing

I tested solution register RST, not solution,

I tested ( add, Capacitor 10uF and 100nF ) on Pin VDDUSB = ok, running, not more problems LOCKUP.

thanks,

Carlos.

[CCandido]

Hi Jing,

I will do tests.

has a strange fact, when I call (serial debug or programmer) it slows down USB CDC errors,

slow down also the resets.

thanks.

Carlos.