Revision 0:8bd0ebc5cbb0, committed 2010-06-09

Comitter:

cedes

Date:

Wed Jun 09 07:47:00 2010 +0000

Commit message:

Changed in this revision

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/main.cpp	Wed Jun 09 07:47:00 2010 +0000
@@ -0,0 +1,116 @@
+#include "mbed.h"
+
+DigitalOut myled1(LED1);
+DigitalOut myled2(LED2);
+DigitalOut myled3(LED3);
+DigitalOut myled4(LED4);
+
+DigitalOut  outGND1(p21);
+PwmOut      fmclck6(p22);
+PwmOut      fmclck5(p23);
+DigitalOut  outGND2(p24);
+PwmOut      fmclck4(p25);
+
+#define PLL0CFG_Val     0x00027
+#define PLL1_SETUP      0
+#define CCLKCFG_Val     5
+#define WAIT_SEC_BEFORE_START   5.0
+
+int main() {
+    // Wait a bit before changing the clock. Who knows, perhaps
+    // it is needed to connect to the device
+    myled1 = 1;
+    wait(WAIT_SEC_BEFORE_START/4.0);
+    myled1 = 0;
+    myled2 = 1;
+    wait(WAIT_SEC_BEFORE_START/4.0);
+    myled2 = 0;
+    myled3 = 1;
+    wait(WAIT_SEC_BEFORE_START/4.0);
+    myled3 = 0;
+    myled4 = 1;
+    wait(WAIT_SEC_BEFORE_START/4.0);
+    myled1 = 1;
+    myled2 = 1;
+    myled3 = 1;
+    myled4 = 1;
+    
+
+
+    // The following sequence must be followed step by step in order to have PLL0 initialized
+    // and running:
+
+    // 1. Disconnect PLL0 with one feed sequence if PLL0 is already connected.
+    LPC_SC->PLL0CON  &= ~0x02;              /* PLL0 Disconnect */
+    LPC_SC->PLL0FEED  = 0xAA;
+    LPC_SC->PLL0FEED  = 0x55;
+
+    // 2. Disable PLL0 with one feed sequence.
+    LPC_SC->PLL0CON  &= ~0x01;              /* PLL0 Disable */
+    LPC_SC->PLL0FEED  = 0xAA;
+    LPC_SC->PLL0FEED  = 0x55;
+
+    // 3. Change the CPU Clock Divider setting to speed up operation without PLL0, if desired.
+//    LPC_SC->CCLKCFG   = 2;                /* Setup Clock Divider "2 + 1 = 3 DIVIDER"  */
+    
+    // 4. Write to the Clock Source Selection Control register to change the clock source if
+    // needed.
+    LPC_SC->CLKSRCSEL = 0x00000001;         /* Select Clock Source for PLL0       */
+    
+    // 5. Write to the PLL0CFG and make it effective with one feed sequence. The PLL0CFG
+    // can only be updated when PLL0 is disabled.
+    LPC_SC->PLL0CFG   = 0x00000013;         /* configure PLL0, N = 1, M = 20 (0x13 + 1) */
+    LPC_SC->PLL0FEED  = 0xAA;
+    LPC_SC->PLL0FEED  = 0x55;
+    
+    // 6. Enable PLL0 with one feed sequence.
+    LPC_SC->PLL0CON  |= 0x01;               /* PLL0 Enable */
+    LPC_SC->PLL0FEED  = 0xAA;
+    LPC_SC->PLL0FEED  = 0x55;
+    
+    // 7. Change the CPU Clock Divider setting for the operation with PLL0. It is critical to do
+    // this before connecting PLL0.
+    LPC_SC->CCLKCFG   = 5;                  /* Setup Clock Divider "5 + 1 = 6 DIVIDER"  */
+    
+    // 8. Wait for PLL0 to achieve lock by monitoring the PLOCK0 bit in the PLL0STAT register,
+    // or using the PLOCK0 interrupt, or wait for a fixed time when the input clock to PLL0 is
+    // slow (i.e. 32 kHz). The value of PLOCK0 may not be stable when the PLL reference
+    // frequency (FREF, the frequency of REFCLK, which is equal to the PLL input
+    // frequency divided by the pre-divider value) is less than 100 kHz or greater than
+    // 20 MHz. In these cases, the PLL may be assumed to be stable after a start-up time
+    // has passed. This time is 500 μs when FREF is greater than 400 kHz and 200 / FREF
+    // seconds when FREF is less than 400 kHz.
+    while (!(LPC_SC->PLL0STAT & (1<<26)));  /* Wait for PLOCK0 */
+    
+    // 9. Connect PLL0 with one feed sequence.
+    LPC_SC->PLL0CON  |= 0x02;               /* PLL0 Connect */
+    LPC_SC->PLL0FEED  = 0xAA;
+    LPC_SC->PLL0FEED  = 0x55;
+    
+    // It is very important not to merge any steps above. For example, do not update the
+    // PLL0CFG and enable PLL0 simultaneously with the same feed sequence.
+
+
+
+    // set PWM
+    outGND1 = 0;                            // Just to have a GND near to the PWMs
+    outGND2 = 0;                            // Just to have a GND near to the PWMs
+    LPC_PWM1->TCR = (1 << 1);               // Reset counter, disable PWM
+    LPC_SC->PCLKSEL0 &= ~(0x3 << 12);
+    LPC_SC->PCLKSEL0 |= (1 << 12);          // Set peripheral clock divider to /1, i.e. system clock
+
+    LPC_PWM1->PCR |= 0x002C;                // Double edge PWM for PWM2,3,5
+
+    LPC_PWM1->MR0 = 3;                      // Match Register 0 is shared period counter for all PWM1
+
+    LPC_PWM1->MR1 = 0;                      // so Match Register 0
+    LPC_PWM1->MR2 = 2;                      // so Match Register 1
+    LPC_PWM1->MR3 = 0;                      // so Match Register 2
+    LPC_PWM1->MR4 = 1;                      // so Match Register 3
+    LPC_PWM1->MR5 = 3;                      // so Match Register 3
+
+    LPC_PWM1->LER |= 1;                     // Start updating at next period start
+    LPC_PWM1->TCR = (1 << 0) || (1 << 3);   // Enable counter and PWM
+
+    while(1);
+}

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mbed.bld	Wed Jun 09 07:47:00 2010 +0000
@@ -0,0 +1,1 @@
+http://mbed.org/users/mbed_official/code/mbed/builds/029aa53d7323