Example of enabling watchdog in KL25Z to prevent block of USBSerial when disconecting serial console

Dependencies:   USBDevice mbed

Code is selfdocumented.

I hope you enyoy it

Files at this revision

API Documentation at this revision

Comitter:
Manel_Marin
Date:
Sat Nov 21 13:24:29 2015 +0000
Commit message:
Working fully documented example

Changed in this revision

KL25Z_SystemInit.c Show annotated file Show diff for this revision Revisions of this file
USBDevice.lib Show annotated file Show diff for this revision Revisions of this file
main.cpp Show annotated file Show diff for this revision Revisions of this file
mbed.bld Show annotated file Show diff for this revision Revisions of this file
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/KL25Z_SystemInit.c	Sat Nov 21 13:24:29 2015 +0000
@@ -0,0 +1,233 @@
+/*
+** ###################################################################
+**     Processor:           MKL25Z128VLK4
+**     Compilers:           ARM Compiler
+**                          Freescale C/C++ for Embedded ARM
+**                          GNU C Compiler
+**                          IAR ANSI C/C++ Compiler for ARM
+**
+**     Reference manual:    KL25RM, Rev.1, Jun 2012
+**     Version:             rev. 1.1, 2012-06-21
+**
+**     Abstract:
+**         Provides a system configuration function and a global variable that
+**         contains the system frequency. It configures the device and initializes
+**         the oscillator (PLL) that is part of the microcontroller device.
+**
+**     Copyright: 2012 Freescale Semiconductor, Inc. All Rights Reserved.
+**
+**     http:                 www.freescale.com
+**     mail:                 support@freescale.com
+**
+**     Revisions:
+**     - rev. 1.0 (2012-06-13)
+**         Initial version.
+**     - rev. 1.1 (2012-06-21)
+**         Update according to reference manual rev. 1.
+**
+** ###################################################################
+*/
+
+/**
+ * @file MKL25Z4
+ * @version 1.1
+ * @date 2012-06-21
+ * @brief Device specific configuration file for MKL25Z4 (implementation file)
+ *
+ * Provides a system configuration function and a global variable that contains
+ * the system frequency. It configures the device and initializes the oscillator
+ * (PLL) that is part of the microcontroller device.
+ */
+
+#include <stdint.h>
+#include "MKL25Z4.h"
+
+//MODIFICATION: We DO want watchdog, uC default after reset is enabled with timeout=1024ms (2^10*LPO=1KHz)
+//#define DISABLE_WDOG    1
+
+#define CLOCK_SETUP     1
+/* Predefined clock setups
+   0 ... Multipurpose Clock Generator (MCG) in FLL Engaged Internal (FEI) mode
+         Reference clock source for MCG module is the slow internal clock source 32.768kHz
+         Core clock = 41.94MHz, BusClock = 13.98MHz
+   1 ... Multipurpose Clock Generator (MCG) in PLL Engaged External (PEE) mode
+         Reference clock source for MCG module is an external crystal 8MHz
+         Core clock = 48MHz, BusClock = 24MHz
+   2 ... Multipurpose Clock Generator (MCG) in Bypassed Low Power External (BLPE) mode
+         Core clock/Bus clock derived directly from an external crystal 8MHz with no multiplication
+         Core clock = 8MHz, BusClock = 8MHz
+   3 ... Multipurpose Clock Generator (MCG) in FLL Engaged External (FEE) mode
+         Reference clock source for MCG module is an external crystal 32.768kHz
+         Core clock = 47.97MHz, BusClock = 23.98MHz
+         This setup sets the RTC to be driven by the MCU clock directly without the need of an external source.
+         RTC register values are retained when MCU is reset although there will be a slight (mSec's)loss of time
+         accuracy durring the reset period. RTC will reset on power down. 
+*/
+
+/*----------------------------------------------------------------------------
+  Define clock source values
+ *----------------------------------------------------------------------------*/
+#if (CLOCK_SETUP == 0)
+    #define CPU_XTAL_CLK_HZ                 8000000u /* Value of the external crystal or oscillator clock frequency in Hz */
+    #define CPU_INT_SLOW_CLK_HZ             32768u   /* Value of the slow internal oscillator clock frequency in Hz  */
+    #define CPU_INT_FAST_CLK_HZ             4000000u /* Value of the fast internal oscillator clock frequency in Hz  */
+    #define DEFAULT_SYSTEM_CLOCK            41943040u /* Default System clock value */
+#elif (CLOCK_SETUP == 1)
+    #define CPU_XTAL_CLK_HZ                 8000000u /* Value of the external crystal or oscillator clock frequency in Hz */
+    #define CPU_INT_SLOW_CLK_HZ             32768u   /* Value of the slow internal oscillator clock frequency in Hz  */
+    #define CPU_INT_FAST_CLK_HZ             4000000u /* Value of the fast internal oscillator clock frequency in Hz  */
+    #define DEFAULT_SYSTEM_CLOCK            48000000u /* Default System clock value */
+#elif (CLOCK_SETUP == 2)
+    #define CPU_XTAL_CLK_HZ                 8000000u /* Value of the external crystal or oscillator clock frequency in Hz */
+    #define CPU_INT_SLOW_CLK_HZ             32768u   /* Value of the slow internal oscillator clock frequency in Hz  */
+    #define CPU_INT_FAST_CLK_HZ             4000000u /* Value of the fast internal oscillator clock frequency in Hz  */
+    #define DEFAULT_SYSTEM_CLOCK            8000000u /* Default System clock value */
+#elif (CLOCK_SETUP == 3)    
+    #define CPU_XTAL_CLK_HZ                 32768u   /* Value of the external crystal or oscillator clock frequency in Hz */
+    #define CPU_INT_SLOW_CLK_HZ             32768u   /* Value of the slow internal oscillator clock frequency in Hz  */
+    #define CPU_INT_FAST_CLK_HZ             4000000u /* Value of the fast internal oscillator clock frequency in Hz  */
+    #define DEFAULT_SYSTEM_CLOCK            47972352u /* Default System clock value */       
+#endif /* (CLOCK_SETUP == 3) */
+
+/* ----------------------------------------------------------------------------
+   -- Core clock
+   ---------------------------------------------------------------------------- */
+
+//MODIFICATION: That vartiable already exists
+// uint32_t SystemCoreClock = DEFAULT_SYSTEM_CLOCK;
+
+/* ----------------------------------------------------------------------------
+   -- SystemInit()
+   ---------------------------------------------------------------------------- */
+
+void $Sub$$SystemInit (void) {
+    
+    //MODIFICATION:
+    // That variable already exists, we set it here
+    SystemCoreClock = DEFAULT_SYSTEM_CLOCK;
+    // We want visual indication of boot time with red LED on
+    //TODO
+
+#if (DISABLE_WDOG)
+  /* Disable the WDOG module */
+  /* SIM_COPC: COPT=0,COPCLKS=0,COPW=0 */
+  SIM->COPC = (uint32_t)0x00u;
+#endif /* (DISABLE_WDOG) */
+#if (CLOCK_SETUP == 0)
+  /* SIM->CLKDIV1: OUTDIV1=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,OUTDIV4=2,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0 */
+  SIM->CLKDIV1 = (uint32_t)0x00020000UL; /* Update system prescalers */
+  /* Switch to FEI Mode */
+  /* MCG->C1: CLKS=0,FRDIV=0,IREFS=1,IRCLKEN=1,IREFSTEN=0 */
+  MCG->C1 = (uint8_t)0x06U;
+  /* MCG_C2: LOCRE0=0,??=0,RANGE0=0,HGO0=0,EREFS0=0,LP=0,IRCS=0 */
+  MCG->C2 = (uint8_t)0x00U;
+  /* MCG->C4: DMX32=0,DRST_DRS=1 */
+  MCG->C4 = (uint8_t)((MCG->C4 & (uint8_t)~(uint8_t)0xC0U) | (uint8_t)0x20U);
+  /* OSC0->CR: ERCLKEN=1,??=0,EREFSTEN=0,??=0,SC2P=0,SC4P=0,SC8P=0,SC16P=0 */
+  OSC0->CR = (uint8_t)0x80U;
+  /* MCG->C5: ??=0,PLLCLKEN0=0,PLLSTEN0=0,PRDIV0=0 */
+  MCG->C5 = (uint8_t)0x00U;
+  /* MCG->C6: LOLIE0=0,PLLS=0,CME0=0,VDIV0=0 */
+  MCG->C6 = (uint8_t)0x00U;
+  while((MCG->S & MCG_S_IREFST_MASK) == 0x00U) { /* Check that the source of the FLL reference clock is the internal reference clock. */
+  }
+  while((MCG->S & 0x0CU) != 0x00U) {    /* Wait until output of the FLL is selected */
+  }
+#elif (CLOCK_SETUP == 1)
+  /* SIM->SCGC5: PORTA=1 */
+  SIM->SCGC5 |= (uint32_t)0x0200UL;     /* Enable clock gate for ports to enable pin routing */
+  /* SIM->CLKDIV1: OUTDIV1=1,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,OUTDIV4=1,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0 */
+  SIM->CLKDIV1 = (uint32_t)0x10010000UL; /* Update system prescalers */
+  /* PORTA->PCR18: ISF=0,MUX=0 */
+  PORTA->PCR[18] &= (uint32_t)~0x01000700UL;
+  /* PORTA->PCR19: ISF=0,MUX=0 */
+  PORTA->PCR[19] &= (uint32_t)~0x01000700UL;
+  /* Switch to FBE Mode */
+  /* OSC0->CR: ERCLKEN=1,??=0,EREFSTEN=0,??=0,SC2P=1,SC4P=0,SC8P=0,SC16P=1 */
+  OSC0->CR = (uint8_t)0x89U;
+  /* MCG->C2: LOCRE0=0,??=0,RANGE0=2,HGO0=0,EREFS0=1,LP=0,IRCS=0 */
+  MCG->C2 = (uint8_t)0x24U;
+  /* MCG->C1: CLKS=2,FRDIV=3,IREFS=0,IRCLKEN=1,IREFSTEN=0 */
+  MCG->C1 = (uint8_t)0x9AU;
+  /* MCG->C4: DMX32=0,DRST_DRS=0 */
+  MCG->C4 &= (uint8_t)~(uint8_t)0xE0U;
+  /* MCG->C5: ??=0,PLLCLKEN0=0,PLLSTEN0=0,PRDIV0=1 */
+  MCG->C5 = (uint8_t)0x01U;
+  /* MCG->C6: LOLIE0=0,PLLS=0,CME0=0,VDIV0=0 */
+  MCG->C6 = (uint8_t)0x00U;
+  while((MCG->S & MCG_S_IREFST_MASK) != 0x00U) { /* Check that the source of the FLL reference clock is the external reference clock. */
+  }
+  while((MCG->S & 0x0CU) != 0x08U) {    /* Wait until external reference clock is selected as MCG output */
+  }
+  /* Switch to PBE Mode */
+  /* MCG->C6: LOLIE0=0,PLLS=1,CME0=0,VDIV0=0 */
+  MCG->C6 = (uint8_t)0x40U;
+  while((MCG->S & 0x0CU) != 0x08U) {    /* Wait until external reference clock is selected as MCG output */
+  }
+  while((MCG->S & MCG_S_LOCK0_MASK) == 0x00U) { /* Wait until locked */
+  }
+  /* Switch to PEE Mode */
+  /* MCG->C1: CLKS=0,FRDIV=3,IREFS=0,IRCLKEN=1,IREFSTEN=0 */
+  MCG->C1 = (uint8_t)0x1AU;
+  while((MCG->S & 0x0CU) != 0x0CU) {    /* Wait until output of the PLL is selected */
+  }
+#elif (CLOCK_SETUP == 2)
+  /* SIM->SCGC5: PORTA=1 */
+  SIM->SCGC5 |= (uint32_t)0x0200UL;     /* Enable clock gate for ports to enable pin routing */
+  /* SIM->CLKDIV1: OUTDIV1=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,OUTDIV4=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0 */
+  SIM->CLKDIV1 = (uint32_t)0x00000000UL; /* Update system prescalers */
+  /* PORTA->PCR18: ISF=0,MUX=0 */
+  PORTA->PCR[18] &= (uint32_t)~0x01000700UL;
+  /* PORTA->PCR19: ISF=0,MUX=0 */
+  PORTA->PCR[19] &= (uint32_t)~0x01000700UL;
+  /* Switch to FBE Mode */
+  /* OSC0->CR: ERCLKEN=1,??=0,EREFSTEN=0,??=0,SC2P=1,SC4P=0,SC8P=0,SC16P=1 */
+  OSC0->CR = (uint8_t)0x89U;
+  /* MCG->C2: LOCRE0=0,??=0,RANGE0=2,HGO0=0,EREFS0=1,LP=0,IRCS=0 */
+  MCG->C2 = (uint8_t)0x24U;
+  /* MCG->C1: CLKS=2,FRDIV=3,IREFS=0,IRCLKEN=1,IREFSTEN=0 */
+  MCG->C1 = (uint8_t)0x9AU;
+  /* MCG->C4: DMX32=0,DRST_DRS=0 */
+  MCG->C4 &= (uint8_t)~(uint8_t)0xE0U;
+  /* MCG->C5: ??=0,PLLCLKEN0=0,PLLSTEN0=0,PRDIV0=0 */
+  MCG->C5 = (uint8_t)0x00U;
+  /* MCG->C6: LOLIE0=0,PLLS=0,CME0=0,VDIV0=0 */
+  MCG->C6 = (uint8_t)0x00U;
+  while((MCG->S & MCG_S_IREFST_MASK) != 0x00U) { /* Check that the source of the FLL reference clock is the external reference clock. */
+  }
+  while((MCG->S & 0x0CU) != 0x08U) {    /* Wait until external reference clock is selected as MCG output */
+  }
+  /* Switch to BLPE Mode */
+  /* MCG->C2: LOCRE0=0,??=0,RANGE0=2,HGO0=0,EREFS0=1,LP=1,IRCS=0 */
+  MCG->C2 = (uint8_t)0x26U;
+  while((MCG->S & 0x0CU) != 0x08U) {    /* Wait until external reference clock is selected as MCG output */
+  }
+#elif (CLOCK_SETUP == 3)  
+/* SIM->SCGC5: PORTA=1 */
+  SIM->SCGC5 |= SIM_SCGC5_PORTA_MASK;   /* Enable clock gate for ports to enable pin routing */
+  /* SIM->CLKDIV1: OUTDIV1=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,OUTDIV4=1,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0 */
+  SIM->CLKDIV1 = (SIM_CLKDIV1_OUTDIV1(0x00) | SIM_CLKDIV1_OUTDIV4(0x01)); /* Update system prescalers */
+  /* PORTA->PCR[3]: ISF=0,MUX=0 */
+  PORTA->PCR[3] &= (uint32_t)~(uint32_t)((PORT_PCR_ISF_MASK | PORT_PCR_MUX(0x07)));
+  /* PORTA->PCR[4]: ISF=0,MUX=0 */
+  PORTA->PCR[4] &= (uint32_t)~(uint32_t)((PORT_PCR_ISF_MASK | PORT_PCR_MUX(0x07)));
+  /* Switch to FEE Mode */
+  /* MCG->C2: LOCRE0=0,??=0,RANGE0=0,HGO0=0,EREFS0=1,LP=0,IRCS=0 */
+  MCG->C2 = (MCG_C2_RANGE0(0x00) | MCG_C2_EREFS0_MASK);
+  /* OSC0->CR: ERCLKEN=1,??=0,EREFSTEN=0,??=0,SC2P=0,SC4P=0,SC8P=0,SC16P=0 */
+  OSC0->CR = OSC_CR_ERCLKEN_MASK | OSC_CR_SC16P_MASK | OSC_CR_SC4P_MASK | OSC_CR_SC2P_MASK;
+  /* MCG->C1: CLKS=0,FRDIV=0,IREFS=0,IRCLKEN=1,IREFSTEN=0 */
+  MCG->C1 = (MCG_C1_CLKS(0x00) | MCG_C1_FRDIV(0x00) | MCG_C1_IRCLKEN_MASK);
+  /* MCG->C4: DMX32=1,DRST_DRS=1 */
+  MCG->C4 = (uint8_t)((MCG->C4 & (uint8_t)~(uint8_t)(
+            MCG_C4_DRST_DRS(0x02)
+           )) | (uint8_t)(
+            MCG_C4_DMX32_MASK |
+            MCG_C4_DRST_DRS(0x01)
+           ));
+  while((MCG->S & MCG_S_IREFST_MASK) != 0x00U) { /* Check that the source of the FLL reference clock is the external reference clock. */
+  }
+  while((MCG->S & 0x0CU) != 0x00U) {    /* Wait until output of the FLL is selected */
+  }          
+#endif /* (CLOCK_SETUP == 3) */
+}
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/USBDevice.lib	Sat Nov 21 13:24:29 2015 +0000
@@ -0,0 +1,1 @@
+http://mbed.org/users/mbed_official/code/USBDevice/#2af474687369
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/main.cpp	Sat Nov 21 13:24:29 2015 +0000
@@ -0,0 +1,52 @@
+#include "mbed.h"
+
+//WATHDOG ENABLED IN OUR KL25Z_SystemInit.c (overloading library function SystemInit.c)
+// It happens in this uC after reset watchdog is enabled with timeout=1024ms (2^10*LPO=1KHz)
+//  so mbed developers to allow a learning use of this board disable it on SystemInit.c
+// **BUT** SIM_COPC register can only be written once after reset and so it can not be enabled later
+//  I think best solution is to overload SystemInit() using:   void $Sub$$SystemInit (void) {
+//  original SystemInit() does not appear in export, it must be dowloaded from:
+// https://developer.mbed.org/users/mbed_official/code/mbed-src/file/a11c0372f0ba/targets/cmsis/TARGET_Freescale/TARGET_KLXX/TARGET_KL25Z/system_MKL25Z4.c
+//  you can arrive there from:
+// https://developer.mbed.org/handbook/mbed-SDK and https://developer.mbed.org/users/mbed_official/code/mbed-src/
+//
+// MORE on this on: https://developer.mbed.org/users/chris/notebook/Patching-functions-and-libraries/
+// and searching "ARM Compiler toolchain Using the Linker" "Using $Super$$ and $Sub$$ to patch symbol definitions"
+
+// Kick (feed, reload) our watchdog timer
+void wdt_kick(){
+    SIM->SRVCOP = (uint32_t)0x55u;
+    SIM->SRVCOP = (uint32_t)0xAAu;
+}
+
+// That set RED LED ON, do that first to evaluate boot time of peripherals
+#define LIGHT 0
+#define DARK 1
+DigitalOut led_red(LED_RED, LIGHT);
+DigitalOut led_green(LED_GREEN, DARK);
+DigitalOut led_blue(LED_BLUE, DARK);
+
+//Virtual serial port over USB using inboard second USB connector (USBKL25Z port)
+#include "USBSerial.h"
+//USBSerial pc;
+//...( vendor_id, product_id, product_release, connect_blocking )
+USBSerial pc( 0x1f00, 0x2012, 0x0001, false );
+//REMEMBER TO USE: class USBSerial -> connect_blocking = false (default is true)
+//  to avoid block of program when no USB cable connected in USBKL25Z port
+//NOTE: USBSerial still blocks program when closing serial terminal, that is fixed by our watchdog
+
+
+int main(void) {
+    //to evaluate boot time I set led RED ON at the beginning of our main.cpp. TODO?: do it in SystemInit?
+    led_blue = DARK;
+    led_green = DARK;
+    led_red = DARK;
+    while(1)
+    {
+        led_blue = LIGHT;
+        pc.printf("I am a virtual serial port\r\n");    // THAT COULD BLOCK
+        wdt_kick();
+        led_blue = DARK;
+        wait(0.5);
+    }
+}
\ No newline at end of file
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mbed.bld	Sat Nov 21 13:24:29 2015 +0000
@@ -0,0 +1,1 @@
+http://mbed.org/users/mbed_official/code/mbed/builds/9296ab0bfc11
\ No newline at end of file