I am trying to configure the internal reference clock for K65F180m in mqx. I have read the utasker documentation on MCG modes and have gone through the reference manual. I have certain doubts regarding MCG. It would be of great help if anyone can clarify them
- For using the IRC, I could find only these configurations. Is there anything more missing (the values configured in registers are mentioned in barckets)
- MCG_C1-> CLKS(1) ,IREFS (1), IRCLKEN(1)
- MCG_C7 ->OSCSEL(2)
- OSC_CR ->ERCLKEN (0)
- MCG_S ->IREFST(1),CLKST(1),IRCST(1)
- SIM_SOPT2 ->PLLFLLSEL (3), SIM_SOPT2_USBSRC_MASK
- USB0_CLK_RECOVER_IRC_EN ->USB_CLK_RECOVER_IRC_EN_REG_EN_MASK
- USB0_CLK_RECOVER_CTRL ->USB_CLK_RECOVER_CTRL_CLOCK_RECOVER_EN_MASK
- When i add the above configurations in my project, the debugging session stops. It might be because of the mismatch in clock. But I read in a post that Jlink OpenSDA won't have issue with lower clock. but mine is openSDA.
- In mqx project, i made the following changes in bsp_cm.c file. i am not sure if this is correct or not
- for making that change i commented off the OSC_CR and mode changing sections in pe_initialize_hardware
/* OSC Configure */
OSC_CR |= ~OSC_CR_ERCLKEN_MASK;
// /* after enter FEI Mode */
- Is it possible to completely remove the external crystal and power up the board. In all the initialization sections, I could see the external reference clock being used in code. Can we do it using the 32KHz and 4MHz crystals available?
- Can we generate the code to use internal reference clock alone for the K65 MCU using processor expert? Is there any document available for the same
- In the MCG documentation, we have MCG in FEI mode when it comes out of reset, Is this reset referring to a full system reset? Does this mean that an external crystal is needed for the MCU operation. Is crystal less operation possible, any document available for the same.