+ /** Starts the DFLL of the XMEGA microcontroller, with the given options.
+ *
+ * \param[in] Source RC Clock source for the DFLL, a value from \ref XMEGA_System_ClockSource_t.
+ * \param[in] Reference Reference clock source for the DFLL, an value from \ref XMEGA_System_DFLLReference_t
+ * \param[in] Frequency Target frequency of the DFLL's output.
+ *
+ * \return Boolean \c true if the DFLL was successfully started, \c false if invalid parameters specified.
+ */
+ static inline bool XMEGACLK_StartDFLL(const uint8_t Source,
+ const uint8_t Reference,
+ const uint32_t Frequency) ATTR_ALWAYS_INLINE;
+ static inline bool XMEGACLK_StartDFLL(const uint8_t Source,
+ const uint8_t Reference,
+ const uint32_t Frequency)
+ {
+ uint16_t DFLLCompare = (Frequency / 1024);
+ uint16_t DFFLCal = 0;
+
+ if (Reference == DFLL_REF_INT_USBSOF)
+ {
+ NVM.CMD = NVM_CMD_READ_CALIB_ROW_gc;
+ DFFLCal = ((0x00 << 8) | pgm_read_byte(offsetof(NVM_PROD_SIGNATURES_t, USBRCOSC)));
+ }
+
+ switch (Source)
+ {
+ case CLOCK_SRC_INT_RC2MHZ:
+ OSC.DFLLCTRL |= (Reference << OSC_RC32MCREF_gp);
+ DFLLRC2M.COMP1 = (DFLLCompare >> 8);
+ DFLLRC2M.COMP2 = (DFLLCompare & 0xFF);
+ DFLLRC2M.CALA = (DFFLCal >> 8);
+ DFLLRC2M.CALB = (DFFLCal & 0xFF);
+ DFLLRC2M.CTRL = DFLL_ENABLE_bm;
+ break;
+ case CLOCK_SRC_INT_RC32MHZ:
+ OSC.DFLLCTRL |= (Reference << OSC_RC32MCREF_gp);
+ DFLLRC32M.COMP1 = (DFLLCompare >> 8);
+ DFLLRC32M.COMP2 = (DFLLCompare & 0xFF);
+ DFLLRC32M.CALA = (DFFLCal >> 8);
+ DFLLRC32M.CALB = (DFFLCal & 0xFF);
+ DFLLRC32M.CTRL = DFLL_ENABLE_bm;
+ break;
+ default:
+ return false;
+ }
+
+ return true;
+ }
+
+ /** Stops the given DFLL of the XMEGA microcontroller.
+ *
+ * \param[in] Source RC Clock source for the DFLL to be stopped, a value from \ref XMEGA_System_ClockSource_t.
+ *
+ * \return Boolean \c true if the DFLL was successfully stopped, \c false if invalid parameters specified.
+ */
+ static inline bool XMEGACLK_StopDFLL(const uint8_t Source) ATTR_ALWAYS_INLINE;
+ static inline bool XMEGACLK_StopDFLL(const uint8_t Source)
+ {
+ switch (Source)
+ {
+ case CLOCK_SRC_INT_RC2MHZ:
+ DFLLRC2M.CTRL = 0;
+ break;
+ case CLOCK_SRC_INT_RC32MHZ:
+ DFLLRC32M.CTRL = 0;
+ break;
+ default:
+ return false;
+ }
+
+ return true;
+ }
+