M263: modify epwm-config-output

Author: cyliangtw

targets/TARGET_NUVOTON/TARGET_M261/device/StdDriver/m261_epwm.c

@@ -103,6 +103,26 @@ uint32_t EPWM_ConfigCaptureChannel(EPWM_T *epwm, uint32_t u32ChannelNum, uint32_
  *       To change duty cycle later, it should get the configured period value and calculate the new comparator value.
  */
 uint32_t EPWM_ConfigOutputChannel(EPWM_T *epwm, uint32_t u32ChannelNum, uint32_t u32Frequency, uint32_t u32DutyCycle)
+{
+    return EPWM_ConfigOutputChannel2(epwm, u32ChannelNum, u32Frequency, u32DutyCycle, 1);
+}
+
+/**
+ * @brief This function Configure EPWM generator and get the nearest frequency in edge aligned(up counter type) auto-reload mode
+ * @param[in] epwm The pointer of the specified EPWM module
+ *                - EPWM0 : EPWM Group 0
+ *                - EPWM1 : EPWM Group 1
+ * @param[in] u32ChannelNum EPWM channel number. Valid values are between 0~5
+ * @param[in] u32Frequency Target generator frequency
+ * @param[in] u32DutyCycle Target generator duty cycle percentage. Valid range are between 0 ~ 100. 10 means 10%, 20 means 20%...
+ * @param[in] u32Frequency2 Target generator frequency = u32Frequency / u32Frequency2
+ * @return Nearest frequency clock in nano second
+ * @note Since every two channels, (0 & 1), (2 & 3), shares a prescaler. Call this API to configure EPWM frequency may affect
+ *       existing frequency of other channel.
+ * @note This function is used for initial stage.
+ *       To change duty cycle later, it should get the configured period value and calculate the new comparator value.
+ */
+uint32_t EPWM_ConfigOutputChannel2(EPWM_T *epwm, uint32_t u32ChannelNum, uint32_t u32Frequency, uint32_t u32DutyCycle, uint32_t u32Frequency2)
 {
     uint32_t u32PWMClockSrc;
     uint32_t i;
@@ -113,14 +133,15 @@ uint32_t EPWM_ConfigOutputChannel(EPWM_T *epwm, uint32_t u32ChannelNum, uint32_t
     {
         u32PWMClockSrc = CLK_GetPCLK0Freq();
     }
-    else /* if((epwm == EPWM1)||(epwm == EPWM1_NS)) */
+    else /* if(epwm == EPWM1) */
     {
         u32PWMClockSrc = CLK_GetPCLK1Freq();
     }
 
     for(u32Prescale = 1U; u32Prescale < 0xFFFU; u32Prescale++)/* prescale could be 0~0xFFF */
     {
-        i = (u32PWMClockSrc / u32Frequency) / u32Prescale;
+        // Note: Support frequency < 1
+        i = (uint64_t) u32PWMClockSrc * u32Frequency2 / u32Frequency / u32Prescale;
         /* If target value is larger than CNR, need to use a larger prescaler */
         if(i <= (0x10000U))
         {

targets/TARGET_NUVOTON/TARGET_M261/device/StdDriver/m261_epwm.h

@@ -541,6 +541,11 @@ extern "C"
 /*---------------------------------------------------------------------------------------------------------*/
 uint32_t EPWM_ConfigCaptureChannel(EPWM_T *epwm, uint32_t u32ChannelNum, uint32_t u32UnitTimeNsec, uint32_t u32CaptureEdge);
 uint32_t EPWM_ConfigOutputChannel(EPWM_T *epwm, uint32_t u32ChannelNum, uint32_t u32Frequency, uint32_t u32DutyCycle);
+uint32_t EPWM_ConfigOutputChannel2(EPWM_T *epwm,
+                                  uint32_t u32ChannelNum,
+                                  uint32_t u32Frequency,
+                                  uint32_t u32DutyCycle,
+                                  uint32_t u32Frequency2);
 void EPWM_Start(EPWM_T *epwm, uint32_t u32ChannelMask);
 void EPWM_Stop(EPWM_T *epwm, uint32_t u32ChannelMask);
 void EPWM_ForceStop(EPWM_T *epwm, uint32_t u32ChannelMask);