system_lpc17xx.c

NXP Cortex-M内核（LPC1700系列）KEIL 调试代码

//                     <3=> Pclk = Hclk / 8
//   </h>
//
//   <h> Power Control for Peripherals Register (PCONP)
//     <o11.1>      PCTIM0: Timer/Counter 0 power/clock enable
//     <o11.2>      PCTIM1: Timer/Counter 1 power/clock enable
//     <o11.3>      PCUART0: UART 0 power/clock enable
//     <o11.4>      PCUART1: UART 1 power/clock enable
//     <o11.6>      PCPWM1: PWM 1 power/clock enable
//     <o11.7>      PCI2C0: I2C interface 0 power/clock enable
//     <o11.8>      PCSPI: SPI interface power/clock enable
//     <o11.9>      PCRTC: RTC power/clock enable
//     <o11.10>     PCSSP1: SSP interface 1 power/clock enable
//     <o11.12>     PCAD: A/D converter power/clock enable
//     <o11.13>     PCCAN1: CAN controller 1 power/clock enable
//     <o11.14>     PCCAN2: CAN controller 2 power/clock enable
//     <o11.15>     PCGPIO: GPIOs power/clock enable
//     <o11.16>     PCRIT: Repetitive interrupt timer power/clock enable
//     <o11.17>     PCMC: Motor control PWM power/clock enable
//     <o11.18>     PCQEI: Quadrature encoder interface power/clock enable
//     <o11.19>     PCI2C1: I2C interface 1 power/clock enable
//     <o11.21>     PCSSP0: SSP interface 0 power/clock enable
//     <o11.22>     PCTIM2: Timer 2 power/clock enable
//     <o11.23>     PCTIM3: Timer 3 power/clock enable
//     <o11.24>     PCUART2: UART 2 power/clock enable
//     <o11.25>     PCUART3: UART 3 power/clock enable
//     <o11.26>     PCI2C2: I2C interface 2 power/clock enable
//     <o11.27>     PCI2S: I2S interface power/clock enable
//     <o11.29>     PCGPDMA: GP DMA function power/clock enable
//     <o11.30>     PCENET: Ethernet block power/clock enable
//     <o11.31>     PCUSB: USB interface power/clock enable
//   </h>
// </e>
*/
#define CLOCK_SETUP           1
#define SCS_Val               0x00000020
#define CLKSRCSEL_Val         0x00000001
#define PLL0_SETUP            1
#define PLL0CFG_Val           0x0000000B
#define PLL1_SETUP            0
#define PLL1CFG_Val           0x00000000
#define CCLKCFG_Val           0x00000003
#define USBCLKCFG_Val         0x00000000
#define PCLKSEL0_Val          0x00000000
#define PCLKSEL1_Val          0x00000000
#define PCONP_Val             0x042887DE


/*--------------------- Flash Accelerator Configuration ----------------------
//
// <e> Flash Accelerator Configuration
//   <o1.0..3>   Flash Accelerator Control Register (FLASHCTRL)
//               <0=> Turned off
//               <8=> Deterministic Mode
//               <9=> Instruction buffering (all branches)
//               <10=> Data buffering.
//               <11=> Instruction and Data buffering (all branches)
//               <13=> Instruction buffering (only backward branches)
//               <15=> Instruction and Data buffering (only backward branches)
//   <o2.0..2>   Flash Accelerator Timing Register (FLASHTIM)
//               <0=> Reserved  <1=> 1   <2=> 2   <3=> 3
//               <4=> 4         <5=> 5   <6=> 6   <7=> 7
//               <i> Fetch Cycles (in CCLK cycles)
// </e>
*/
#define FLASH_SETUP           1
#define FLASHCTRL_Val         0x0000000B
#define FLASHTIM_Val          0x00000003

/*
//-------- <<< end of configuration section >>> ------------------------------
*/

/*----------------------------------------------------------------------------
  Check the register settings
 *----------------------------------------------------------------------------*/
#define CHECK_RANGE(val, min, max)                ((val < min) || (val > max))
#define CHECK_RSVD(val, mask)                     (val & mask)

/* Clock Configuration -------------------------------------------------------*/
#if (CHECK_RSVD((SCS_Val),       ~0x00000030))
   #error "SCS: Invalid values of reserved bits!"
#endif

#if (CHECK_RANGE((CLKSRCSEL_Val), 0, 2))
   #error "CLKSRCSEL: Value out of range!"
#endif

#if (CHECK_RSVD((PLL0CFG_Val),   ~0x00FF7FFF))
   #error "PLL0CFG: Invalid values of reserved bits!"
#endif

#if (CHECK_RSVD((PLL1CFG_Val),   ~0x0000007F))
   #error "PLL1CFG: Invalid values of reserved bits!"
#endif

#if ((CCLKCFG_Val != 0) && (((CCLKCFG_Val - 1) % 2)))
   #error "CCLKCFG: CCLKSEL field does not contain only odd values or 0!"
#endif

#if (CHECK_RSVD((USBCLKCFG_Val), ~0x0000000F))
   #error "USBCLKCFG: Invalid values of reserved bits!"
#endif

#if (CHECK_RSVD((PCLKSEL0_Val),   0x000C0C00))
   #error "PCLKSEL0: Invalid values of reserved bits!"
#endif

#if (CHECK_RSVD((PCLKSEL1_Val),   0x03000300))
   #error "PCLKSEL1: Invalid values of reserved bits!"
#endif

#if (CHECK_RSVD((PCONP_Val),      0x10100821))
   #error "PCONP: Invalid values of reserved bits!"
#endif

/* Flash Accelerator Configuration -------------------------------------------*/
#if (CHECK_RSVD((FLASHCTRL_Val), ~0x0000000F))
   #error "FLASHCTRL: Invalid values of reserved bits!"
#endif

#if (CHECK_RSVD((FLASHTIM_Val),  ~0x00000007))
   #error "FLASHTIM: Invalid values of reserved bits!"
#endif


/*----------------------------------------------------------------------------
  DEFINES
 *----------------------------------------------------------------------------*/
    
/*----------------------------------------------------------------------------
  Define clocks
 *----------------------------------------------------------------------------*/
#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   */


/*----------------------------------------------------------------------------
  Clock Variable definitions
 *----------------------------------------------------------------------------*/
uint32_t SystemFrequency = IRC_OSC; /*!< System Clock Frequency (Core Clock)  */


/**
 * 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                        */
  SC->SCS       = SCS_Val;
  if (SCS_Val & (1 << 5)) {             /* If Main Oscillator is enabled      */
    while ((SC->SCS & (1 << 6)) == 0);  /* Wait for Oscillator to be ready    */
  }

#if (PLL0_SETUP)
  SC->CLKSRCSEL = CLKSRCSEL_Val;        /* Select Clock Source for PLL0       */
  SC->PLL0CFG   = PLL0CFG_Val;
  SC->PLL0CON   = 0x01;                 /* PLL0 Enable                        */
  SC->PLL0FEED  = 0xAA;
  SC->PLL0FEED  = 0x55;
  while (!(SC->PLL0STAT & (1 << 26)));  /* Wait for PLOCK0                    */
  SC->CCLKCFG   = CCLKCFG_Val;          /* Setup Clock Divider                */

  SC->PLL0CON   = 0x03;                 /* PLL0 Enable & Connect              */
  SC->PLL0FEED  = 0xAA;
  SC->PLL0FEED  = 0x55;
#endif

#if (PLL1_SETUP)
  SC->PLL1CFG   = PLL1CFG_Val;
  SC->PLL1CON   = 0x01;                 /* PLL1 Enable                        */
  SC->PLL1FEED  = 0xAA;
  SC->PLL1FEED  = 0x55;
  while (!(SC->PLL1STAT & (1 << 26)));  /* Wait for PLOCK1                    */

  SC->PLL1CON   = 0x03;                 /* PLL1 Enable & Connect              */
  SC->PLL1FEED  = 0xAA;
  SC->PLL1FEED  = 0x55;
#endif
#endif

  /* Determine clock frequency according to clock register values             */
  if (((SC->PLL0STAT >> 24) & 3) == 3) {/* If PLL0 enabled and connected      */
    switch (SC->CLKSRCSEL & 0x03) {
      case 0:                           /* Internal RC oscillator => PLL0     */
      case 3:                           /* Reserved, default to Internal RC   */
        SystemFrequency = (IRC_OSC * 
                          (((2 * ((SC->PLL0STAT & 0x7FFF) + 1))) /
                          (((SC->PLL0STAT >> 16) & 0xFF) + 1))   /
                          ((SC->CCLKCFG & 0xFF)+ 1));
        break;
      case 1:                           /* Main oscillator => PLL0            */
        SystemFrequency = (OSC_CLK * 
                          (((2 * ((SC->PLL0STAT & 0x7FFF) + 1))) /
                          (((SC->PLL0STAT >> 16) & 0xFF) + 1))   /
                          ((SC->CCLKCFG & 0xFF)+ 1));
        break;
      case 2:                           /* RTC oscillator => PLL0             */
        SystemFrequency = (RTC_CLK * 
                          (((2 * ((SC->PLL0STAT & 0x7FFF) + 1))) /
                          (((SC->PLL0STAT >> 16) & 0xFF) + 1))   /
                          ((SC->CCLKCFG & 0xFF)+ 1));
        break;
    }
  } else {
    switch (SC->CLKSRCSEL & 0x03) {
      case 0:                           /* Internal RC oscillator => PLL0     */
      case 3:                           /* Reserved, default to Internal RC   */
        SystemFrequency = IRC_OSC / ((SC->CCLKCFG & 0xFF)+ 1);
        break;
      case 1:                           /* Main oscillator => PLL0            */
        SystemFrequency = OSC_CLK / ((SC->CCLKCFG & 0xFF)+ 1);
        break;
      case 2:                           /* RTC oscillator => PLL0             */
        SystemFrequency = RTC_CLK / ((SC->CCLKCFG & 0xFF)+ 1);
        break;
    }
  }

#if (FLASH_SETUP == 1)                  /* Flash Accelerator Setup            */
  SC->FLASHTIM  = FLASHTIM_Val;
  SC->FLASHCTRL = FLASHCTRL_Val;
#endif
}