topic Problem with K70 USB device connection on custom hardware ... in Kinetis Microcontrollers https://community.nxp.com/t5/Kinetis-Microcontrollers/Problem-with-K70-USB-device-connection-on-custom-hardware/m-p/294075#M11954 <HTML><HEAD></HEAD><BODY><P>Hi,</P><P></P><P>I have an custome hardware based on a Kinetis K70 uC. The USB device is connected to the D+ and D- signals of the USB interface using a mini USB connector (the traces go straight from the connector to the chip pins). The custom hardware is almost identical to the K70 tower hardware.</P><P></P><P>I can run most of the MQX example programs on this board but run into a problem regarding the USB CDC-ACM example. When I plug the USB cable into the board, the JTAG interface unit LEDs go dark and my debugger in uVision crashes.</P><P></P><P>I double checked the connections, the lines are connected correctly. What I noticed is that the USB 5V input is not connected to VREGIN, instead it is connected to an GPIO for detecting a change.</P><P></P><P>Since connecting the USB seems so simple, what could be wrong? Dop I need to change the configuration since VREGIN is not conncted? Any advice is appreciated.</P><P></P><P>Thank you!</P><P></P><P>Frank</P></BODY></HTML> Wed, 12 Mar 2014 06:56:14 GMT Baerchen 2014-03-12T06:56:14Z Problem with K70 USB device connection on custom hardware ... https://community.nxp.com/t5/Kinetis-Microcontrollers/Problem-with-K70-USB-device-connection-on-custom-hardware/m-p/294075#M11954 <HTML><HEAD></HEAD><BODY><P>Hi,</P><P></P><P>I have an custome hardware based on a Kinetis K70 uC. The USB device is connected to the D+ and D- signals of the USB interface using a mini USB connector (the traces go straight from the connector to the chip pins). The custom hardware is almost identical to the K70 tower hardware.</P><P></P><P>I can run most of the MQX example programs on this board but run into a problem regarding the USB CDC-ACM example. When I plug the USB cable into the board, the JTAG interface unit LEDs go dark and my debugger in uVision crashes.</P><P></P><P>I double checked the connections, the lines are connected correctly. What I noticed is that the USB 5V input is not connected to VREGIN, instead it is connected to an GPIO for detecting a change.</P><P></P><P>Since connecting the USB seems so simple, what could be wrong? Dop I need to change the configuration since VREGIN is not conncted? Any advice is appreciated.</P><P></P><P>Thank you!</P><P></P><P>Frank</P></BODY></HTML> Wed, 12 Mar 2014 06:56:14 GMT https://community.nxp.com/t5/Kinetis-Microcontrollers/Problem-with-K70-USB-device-connection-on-custom-hardware/m-p/294075#M11954 Baerchen 2014-03-12T06:56:14Z Re: Problem with K70 USB device connection on custom hardware ... https://community.nxp.com/t5/Kinetis-Microcontrollers/Problem-with-K70-USB-device-connection-on-custom-hardware/m-p/294076#M11955 <HTML><HEAD></HEAD><BODY><P>I believe the mcu is resetting, check the SRS registers to know the origin of the last reset source:</P><UL><LI><STRONG>RCM_SRS0</STRONG></LI><LI><STRONG>RCM_SRS1</STRONG></LI></UL></BODY></HTML> Tue, 18 Mar 2014 20:34:55 GMT https://community.nxp.com/t5/Kinetis-Microcontrollers/Problem-with-K70-USB-device-connection-on-custom-hardware/m-p/294076#M11955 apanecatl 2014-03-18T20:34:55Z Re: Problem with K70 USB device connection on custom hardware ... https://community.nxp.com/t5/Kinetis-Microcontrollers/Problem-with-K70-USB-device-connection-on-custom-hardware/m-p/294077#M11956 <HTML><HEAD></HEAD><BODY><P>Hi Pedro,</P><P></P><P>why would the CPU go through reset in this situation? I will try it out.</P><P></P><P>My other question is, can the USB device interface work without having VREGIN connected?</P><P></P><P>Thank you.</P></BODY></HTML> Fri, 21 Mar 2014 07:52:23 GMT https://community.nxp.com/t5/Kinetis-Microcontrollers/Problem-with-K70-USB-device-connection-on-custom-hardware/m-p/294077#M11956 Baerchen 2014-03-21T07:52:23Z