topic Re: LPC1114 Crystal in LPCXpresso IDE

LPC1114 Crystal

lpcware — Thu, 16 Jun 2016 02:41:18 GMT

Content originally posted in LPCWare by JAAA on Thu Jun 30 06:28:24 MST 2011
Hello

I have a lpc1114 connected with 25 MHz external cyrstal. The lpc1114 MCU internal crystal is 12 MHz. Through the pin 3 (RESET), pin 29 (SWCLK) and pin 39 (SWDIO), I connect the MCU to LPC - Link. My question is why can not debug? It is possible?

Re: LPC1114 Crystal

lpcware — Thu, 16 Jun 2016 02:41:19 GMT

Content originally posted in LPCWare by Ex-Zero on Thu Jun 30 06:42:53 MST 2011

Quote: JAAA
...is why can not debug? It is possible?

Don't know why it's not working. It's possible :) and therefore I would guess you have a hardware problem or did forget to change PLL settings :confused:

Re: LPC1114 Crystal

lpcware — Thu, 16 Jun 2016 02:41:20 GMT

Content originally posted in LPCWare by JSalisbury on Thu Jun 30 09:05:45 MST 2011
The problem is that the device could be trying to start up against the external crystal, and the device is unstable against the unlocked PLL. To fix the problem use Flashmagic and a USB to TTL uart. This will let you use flash magic to reprogram the device.

Note to NXP, it would be usefull if the blinky project checked for unlocked PLL before switching to the PLL output!

Re: LPC1114 Crystal

lpcware — Thu, 16 Jun 2016 02:41:20 GMT

Content originally posted in LPCWare by Ex-Zero on Thu Jun 30 09:25:42 MST 2011

Quote: JSalisbury
Note to NXP, it would be usefull if the blinky project checked for unlocked PLL before switching to the PLL output!

Isn't

  LPC_SYSCON->SYSPLLCTRL    = SYSPLLCTRL_Val;
  LPC_SYSCON->PDRUNCFG     &= ~(1 << 7);          /* Power-up SYSPLL          */
  while (!(LPC_SYSCON->SYSPLLSTAT & 0x01));          /* Wait Until PLL Locked    */

in System_LPC11xx.c doing that :confused:

Re: LPC1114 Crystal

lpcware — Thu, 16 Jun 2016 02:41:21 GMT

Content originally posted in LPCWare by kendwyer on Thu Jun 30 16:21:33 MST 2011
The LPC1114 will always boot from IRC regardless of the external Xtal connected - assuming you are not driving the Xtal pins beyond ~1.8v.

If it is a non programmed part it should be still possible to connect with SWD.