F29H85X-SOM-EVM: Running from single-ended 25 MHz CMOS clock

Part Number: F29H85X-SOM-EVM

Tool/software:

Hello TI Experts,

I am trying to run the "led_ex1_blinky" demo from the external 25 MHz clock. 

The system configurator (see screenshot below) generates the following code:

	//
    // Set up PLL control and clock dividers
    //
	SysCtl_setClock(SYSCTL_OSCSRC_XTAL_SE, SYSCTL_PLL_ENABLE, SYSCTL_REFDIV_2, 
					SYSCTL_IMULT_32, SYSCTL_ODIV_2, SYSCTL_SYSDIV_1, DCC1_BASE);

But the code will not run with this setting.

C29xx_CPU1: Error: (Error 0xFFFFFB6E - hpti_context_cmapi:GetTargetStatus:413) Unable to access the DAP. Reset the device, and retry the operation. If error persists, confirm configuration, power-cycle the board, and/or try more reliable JTAG settings (e.g. lower TCLK). (Emulation package 20.1.0.3372)

On the other hand, the MCU runs just fine from the internal oscillator:

	SysCtl_setClock(SYSCTL_OSCSRC_OSC2, SYSCTL_PLL_ENABLE, SYSCTL_REFDIV_1, 
					SYSCTL_IMULT_40, SYSCTL_ODIV_2, SYSCTL_SYSDIV_1, DCC1_BASE);

Any idea what might be going on? I did check the documentation and errata and was unable to find anything that would suggest the MCU or SOM should not support this external clocking.

Thank you in advance and kind regards,

Beat