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added DCO-resync function and default config

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This commit is contained in:
joxe 2009-02-04 18:28:44 +00:00
parent 80feb7ad57
commit 80848e4106
2 changed files with 60 additions and 2 deletions
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50
cpu/msp430/msp430.c
View file

@ -28,7 +28,7 @@
*
* This file is part of the Contiki operating system.
*
* @(#)$Id: msp430.c,v 1.9 2008/02/11 10:44:49 adamdunkels Exp $
* @(#)$Id: msp430.c,v 1.10 2009/02/04 18:28:44 joxe Exp $
*/
#include <io.h>
#include <signal.h>
@ -94,6 +94,7 @@ msp430_init_dco(void)
BCSCTL1 &= ~(DIVA1 + DIVA0); /* remove /8 divisor from ACLK again */
}
/*---------------------------------------------------------------------------*/
static void
init_ports(void)
{
@ -220,3 +221,50 @@ splx_(int sr)
asmv("bis %0, r2" : : "r" (sr));
}
/*---------------------------------------------------------------------------*/
/* this code will always start the TimerB if not already started */
void
msp430_sync_dco(void) {
uint16_t last;
uint16_t diff;
/* uint32_t speed; */
/* DELTA_2 assumes an ACLK of 32768 Hz */
#define DELTA_2 ((MSP430_CPU_SPEED) / 32768)
/* Select SMCLK clock, and capture on ACLK for TBCCR6 */
TBCTL = TBSSEL1 | TBCLR;
TBCCTL6 = CCIS0 + CM0 + CAP;
/* start the timer */
TBCTL |= MC1;
// wait for next Capture
TBCCTL6 &= ~CCIFG;
while(!(TBCCTL6 & CCIFG));
last = TBCCR6;
TBCCTL6 &= ~CCIFG;
// wait for next Capture - and calculate difference
while(!(TBCCTL6 & CCIFG));
diff = TBCCR6 - last;
/* Stop timer - conserves energy according to user guide */
TBCTL = 0;
/* speed = diff; */
/* speed = speed * 32768; */
/* printf("Last TAR diff:%d target: %ld ", diff, DELTA_2); */
/* printf("CPU Speed: %lu DCOCTL: %d\n", speed, DCOCTL); */
/* resynchronize the DCO speed if not at target */
if(DELTA_2 < diff) { /* DCO is too fast, slow it down */
DCOCTL--;
if(DCOCTL == 0xFF) { /* Did DCO role under? */
BCSCTL1--;
}
} else if (DELTA_2 > diff) {
DCOCTL++;
if(DCOCTL == 0x00) { /* Did DCO role over? */
BCSCTL1++;
}
}
}
/*---------------------------------------------------------------------------*/

12
cpu/msp430/msp430def.h
View file

@ -26,7 +26,7 @@
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* @(#)$Id: msp430def.h,v 1.1 2007/08/16 13:09:06 bg- Exp $
* @(#)$Id: msp430def.h,v 1.2 2009/02/04 18:28:44 joxe Exp $
*/
#ifndef MSP430DEF_H
@ -49,7 +49,17 @@ typedef uint16_t u16_t;
typedef uint32_t u32_t;
typedef int32_t s32_t;
/* default DCOSYNCH Period is 30 seconds */
#ifdef DCOSYNCH_CONF_PERIOD
#define DCOSYNCH_PERIOD DCOSYNCH_CONF_PERIOD
#else
#define DCOSYNCH_PERIOD 30
#endif
void msp430_cpu_init(void); /* Rename to cpu_init() later! */
void msp430_sync_dco(void);
#define cpu_init() msp430_cpu_init()
void *sbrk(int);