Hello,
I have replaced the default Arduino Due 12 Mhz oscillator by a 12 Mhz TCXO (Temperature Compensated Crystal Oscillator). The TCXO output is connected to the XIN pin of the SAM3X8E microcontroller.
I read the datasheet and found this:
• MOSCXTBY: Main Crystal Oscillator Bypass
0 = No effect.
1 = The Main Crystal Oscillator is bypassed. MOSCXTEN must be set to 0. An external clock must be connected on XIN.
When MOSCXTBY is set, the MOSCXTS flag in PMC_SR is automatically set.
Clearing MOSCXTEN and MOSCXTBY bits allows resetting the MOSCXTS flag.
So I replaced the defined CKGR_MOR_MOSCXTEN by CKGR_MOR_MOSCXTBY on the file "Device_Startup\system_sam3xa.c" in order to use the bypass mode.
After that replace on the file my Arduino Due is working fine with my TCXO.
Do I have to add or fix something else on the "Device_Startup\system_sam3xa.c" file?
Am I wrong on something?
I'm new in this forum and also new with Arduno Due.
Regards
Alfred