Linux/TM4C123GH6PM: cannot use external XTAL

Hello Minh,

I think your issue here is that you are telling the System Control that you are using a 16 MHz crystal:

SysCtlClockSet(SYSCTL_SYSDIV_2_5 | SYSCTL_USE_PLL | SYSCTL_XTAL_16MHZ | SYSCTL_OSC_MAIN);

Instead replace SYSCTL_XTAL_16MHZ with SYSCTL_XTAL_8MHZ so it recognizes you are using an 8 MHz crystal:

SysCtlClockSet(SYSCTL_SYSDIV_2_5 | SYSCTL_USE_PLL | SYSCTL_XTAL_8MHZ | SYSCTL_OSC_MAIN);

oh I'm so sorry. I have some mistake in write down my thinking. I mean I use the XTAL 16Mhz. Thank for your help but my XTAL seem not work eventhough I try 4 different XTAL and 2 microcontroller TM4C123. The code work with Tiva launchpad but my board.

Hello Minh,

I don't think that's a code issue, it could be a hardware issue. Can you post schematic and also a picture of the MCU & XTAL so I can see how close they are etc.?

Some picture of my board.

I'm sure the capacitor is 10pF 

when i try 

SysCtlClockSet(SYSCTL_SYSDIV_10 | SYSCTL_USE_PLL | SYSCTL_OSC_MAIN | SYSCTL_XTAL_16MHZ);

or others bigger, the code work at fist but suddenly stop after 1-2s.

but when i didn't use PLL, 

SysCtlClockSet( SYSCTL_XTAL_16MHZ |  SYSCTL_OSC_MAIN |SYSCTL_USE_OSC);

The code work well.

This is my schematic. is there a problem in schematic that affect the PLL?

my_lv_board.pdf

Could you give me some idea, please.

Thank you.

oh, I am sorry about the schematics make you misunderstanding. But I am sure that i used the 16Mhz XTAL not 48 Mhz.

I were a bit lazy when i made this board. so i use the 48Mhz and forgot to change the name of that XTAL.

i am apologize for my negligent.