Diff: targets/TARGET_NXP/TARGET_LPC23XX/device/system_LPC23xx.c

Revision:

149:156823d33999

Parent:

144:ef7eb2e8f9f7

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/targets/TARGET_NXP/TARGET_LPC23XX/device/system_LPC23xx.c	Fri Oct 28 11:17:30 2016 +0100
@@ -0,0 +1,144 @@
+/* mbed Microcontroller Library
+ * Copyright (C) 2008-2009 ARM Limited. All rights reserved.
+ *
+ * ARM7 version of CMSIS-like functionality - not advised for use outside mbed!
+ */
+
+#include <stdint.h>
+#include "LPC23xx.h"
+
+#define CLOCK_SETUP           1
+#define SCS_Val               0x00000020
+#define CLKSRCSEL_Val         0x00000001
+
+#define PLL0_SETUP            1
+#define PLL0CFG_Val           0x00000013
+#define CCLKCFG_Val           0x00000007
+#define USBCLKCFG_Val         0x00000009
+#define PCLKSEL0_Val          0x00000000
+#define PCLKSEL1_Val          0x00000000
+#define PCONP_Val             0x042887DE
+#define CLKOUTCFG_Val         0x00000000
+#define MAMCR_Val             0x00000001  // there is a bug in the MAM so it should never be fully enabled (only disabled or partially enabled)
+#define MAMTIM_Val            0x00000004
+
+/*----------------------------------------------------------------------------
+  DEFINES
+ *----------------------------------------------------------------------------*/
+    
+#define XTAL        (12000000UL)        /* Oscillator frequency               */
+#define OSC_CLK     (      XTAL)        /* Main oscillator frequency          */
+#define RTC_CLK     (   32000UL)        /* RTC oscillator frequency           */
+#define IRC_OSC     ( 4000000UL)        /* Internal RC oscillator frequency   */
+
+/* F_cco0 = (2 * M * F_in) / N  */
+#define __M               (((PLL0CFG_Val      ) & 0x7FFF) + 1)
+#define __N               (((PLL0CFG_Val >> 16) & 0x00FF) + 1)
+#define __FCCO(__F_IN)    ((2 * __M * __F_IN) / __N) 
+#define __CCLK_DIV        (((CCLKCFG_Val      ) & 0x00FF) + 1)
+
+/* Determine core clock frequency according to settings */
+ #if (PLL0_SETUP)
+    #if   ((CLKSRCSEL_Val & 0x03) == 1)
+        #define __CORE_CLK (__FCCO(OSC_CLK) / __CCLK_DIV)
+    #elif ((CLKSRCSEL_Val & 0x03) == 2)
+        #define __CORE_CLK (__FCCO(RTC_CLK) / __CCLK_DIV)
+    #else 
+        #define __CORE_CLK (__FCCO(IRC_OSC) / __CCLK_DIV)
+    #endif
+ #endif
+
+
+/*----------------------------------------------------------------------------
+  Clock Variable definitions
+ *----------------------------------------------------------------------------*/
+uint32_t SystemCoreClock = __CORE_CLK;/*!< System Clock Frequency (Core Clock)*/
+
+/*----------------------------------------------------------------------------
+  Clock functions
+ *----------------------------------------------------------------------------*/
+void SystemCoreClockUpdate (void)            /* Get Core Clock Frequency      */
+{
+  /* Determine clock frequency according to clock register values             */
+  if (((LPC_SC->PLL0STAT >> 24) & 3) == 3) { /* If PLL0 enabled and connected */
+    switch (LPC_SC->CLKSRCSEL & 0x03) {
+      case 0:                                /* Int. RC oscillator => PLL0    */
+      case 3:                                /* Reserved, default to Int. RC  */
+        SystemCoreClock = (IRC_OSC * 
+                          (((2 * ((LPC_SC->PLL0STAT & 0x7FFF) + 1))) /
+                          (((LPC_SC->PLL0STAT >> 16) & 0xFF) + 1))   /
+                          ((LPC_SC->CCLKCFG & 0xFF)+ 1));
+        break;
+      case 1:                                /* Main oscillator => PLL0       */
+        SystemCoreClock = (OSC_CLK * 
+                          (((2 * ((LPC_SC->PLL0STAT & 0x7FFF) + 1))) /
+                          (((LPC_SC->PLL0STAT >> 16) & 0xFF) + 1))   /
+                          ((LPC_SC->CCLKCFG & 0xFF)+ 1));
+        break;
+      case 2:                                /* RTC oscillator => PLL0        */
+        SystemCoreClock = (RTC_CLK * 
+                          (((2 * ((LPC_SC->PLL0STAT & 0x7FFF) + 1))) /
+                          (((LPC_SC->PLL0STAT >> 16) & 0xFF) + 1))   /
+                          ((LPC_SC->CCLKCFG & 0xFF)+ 1));
+        break;
+    }
+  } else {
+    switch (LPC_SC->CLKSRCSEL & 0x03) {
+      case 0:                                /* Int. RC oscillator => PLL0    */
+      case 3:                                /* Reserved, default to Int. RC  */
+        SystemCoreClock = IRC_OSC / ((LPC_SC->CCLKCFG & 0xFF)+ 1);
+        break;
+      case 1:                                /* Main oscillator => PLL0       */
+        SystemCoreClock = OSC_CLK / ((LPC_SC->CCLKCFG & 0xFF)+ 1);
+        break;
+      case 2:                                /* RTC oscillator => PLL0        */
+        SystemCoreClock = RTC_CLK / ((LPC_SC->CCLKCFG & 0xFF)+ 1);
+        break;
+    }
+  }
+}
+
+/**
+ * Initialize the system
+ *
+ * @param  none
+ * @return none
+ *
+ * @brief  Setup the microcontroller system.
+ *         Initialize the System and update the SystemFrequency variable.
+ */
+void SystemInit (void)
+{
+#if (CLOCK_SETUP)                       /* Clock Setup                        */
+  LPC_SC->SCS       = SCS_Val;
+  if (SCS_Val & (1 << 5)) {             /* If Main Oscillator is enabled      */
+    while ((LPC_SC->SCS & (1 << 6)) == 0);  /* Wait for Oscillator to be ready    */
+  }
+
+  LPC_SC->CCLKCFG   = CCLKCFG_Val;          /* Setup Clock Divider                */
+
+#if (PLL0_SETUP)
+  LPC_SC->CLKSRCSEL = CLKSRCSEL_Val;        /* Select Clock Source for PLL0       */
+  LPC_SC->PLL0CFG   = PLL0CFG_Val;
+  LPC_SC->PLL0CON   = 0x01;                 /* PLL0 Enable                        */
+  LPC_SC->PLL0FEED  = 0xAA;
+  LPC_SC->PLL0FEED  = 0x55;
+  while (!(LPC_SC->PLL0STAT & (1 << 26)));  /* Wait for PLOCK0                    */
+
+  LPC_SC->PLL0CON   = 0x03;                 /* PLL0 Enable & Connect              */
+  LPC_SC->PLL0FEED  = 0xAA;
+  LPC_SC->PLL0FEED  = 0x55;
+#endif
+
+  LPC_SC->USBCLKCFG = USBCLKCFG_Val;        /* Setup USB Clock Divider            */
+#endif
+
+  LPC_SC->PCLKSEL0  = PCLKSEL0_Val;         /* Peripheral Clock Selection         */
+  LPC_SC->PCLKSEL1  = PCLKSEL1_Val;
+
+  LPC_SC->PCONP     = PCONP_Val;            /* Power Control for Peripherals      */
+    
+  // Setup MAM
+  LPC_SC->MAMTIM      = MAMTIM_Val;
+  LPC_SC->MAMCR       = MAMCR_Val;
+}