nes-proj/cpu/msp430/msp430.c

271 lines
7.5 KiB
C

/*
* Copyright (c) 2005, Swedish Institute of Computer Science
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the Institute nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* This file is part of the Contiki operating system.
*
* @(#)$Id: msp430.c,v 1.10 2009/02/04 18:28:44 joxe Exp $
*/
#include <io.h>
#include <signal.h>
#include <sys/unistd.h>
#include "msp430.h"
#include "dev/watchdog.h"
#include "net/uip.h"
/*---------------------------------------------------------------------------*/
void
msp430_init_dco(void)
{
/* This code taken from the FU Berlin sources and reformatted. */
#define DELTA ((MSP430_CPU_SPEED) / (32768 / 8))
unsigned int compare, oldcapture = 0;
unsigned int i;
BCSCTL1 = 0xa4; /* ACLK is devided by 4. RSEL=6 no division for MCLK
and SSMCLK. XT2 is off. */
BCSCTL2 = 0x00; /* Init FLL to desired frequency using the 32762Hz
crystal DCO frquenzy = 2,4576 MHz */
BCSCTL1 |= DIVA1 + DIVA0; /* ACLK = LFXT1CLK/8 */
for(i = 0xffff; i > 0; i--) { /* Delay for XTAL to settle */
asm("nop");
}
CCTL2 = CCIS0 + CM0 + CAP; // Define CCR2, CAP, ACLK
TACTL = TASSEL1 + TACLR + MC1; // SMCLK, continous mode
while(1) {
while((CCTL2 & CCIFG) != CCIFG); /* Wait until capture occured! */
CCTL2 &= ~CCIFG; /* Capture occured, clear flag */
compare = CCR2; /* Get current captured SMCLK */
compare = compare - oldcapture; /* SMCLK difference */
oldcapture = CCR2; /* Save current captured SMCLK */
if(DELTA == compare) {
break; /* if equal, leave "while(1)" */
} else if(DELTA < compare) { /* DCO is too fast, slow it down */
DCOCTL--;
if(DCOCTL == 0xFF) { /* Did DCO role under? */
BCSCTL1--;
}
} else { /* -> Select next lower RSEL */
DCOCTL++;
if(DCOCTL == 0x00) { /* Did DCO role over? */
BCSCTL1++;
}
/* -> Select next higher RSEL */
}
}
CCTL2 = 0; /* Stop CCR2 function */
TACTL = 0; /* Stop Timer_A */
BCSCTL1 &= ~(DIVA1 + DIVA0); /* remove /8 divisor from ACLK again */
}
/*---------------------------------------------------------------------------*/
static void
init_ports(void)
{
/* Turn everything off, device drivers enable what is needed. */
/* All configured for digital I/O */
#ifdef P1SEL
P1SEL = 0;
#endif
#ifdef P2SEL
P2SEL = 0;
#endif
#ifdef P3SEL
P3SEL = 0;
#endif
#ifdef P4SEL
P4SEL = 0;
#endif
#ifdef P5SEL
P5SEL = 0;
#endif
#ifdef P6SEL
P6SEL = 0;
#endif
/* All available inputs */
#ifdef P1DIR
P1DIR = 0;
P1OUT = 0;
#endif
#ifdef P2DIR
P2DIR = 0;
P2OUT = 0;
#endif
#ifdef P3DIR
P3DIR = 0;
P3OUT = 0;
#endif
#ifdef P4DIR
P4DIR = 0;
P4OUT = 0;
#endif
#ifdef P5DIR
P5DIR = 0;
P5OUT = 0;
#endif
#ifdef P6DIR
P6DIR = 0;
P6OUT = 0;
#endif
P1IE = 0;
P2IE = 0;
}
/*---------------------------------------------------------------------------*/
/* msp430-ld may align _end incorrectly. Workaround in cpu_init. */
extern int _end; /* Not in sys/unistd.h */
static char *cur_break = (char *)&_end;
void
msp430_cpu_init(void)
{
dint();
watchdog_init();
init_ports();
msp430_init_dco();
eint();
if((uintptr_t)cur_break & 1) { /* Workaround for msp430-ld bug! */
cur_break++;
}
}
/*---------------------------------------------------------------------------*/
#define asmv(arg) __asm__ __volatile__(arg)
#define STACK_EXTRA 32
/*
* Allocate memory from the heap. Check that we don't collide with the
* stack right now (some other routine might later). A watchdog might
* be used to check if cur_break and the stack pointer meet during
* runtime.
*/
void *
sbrk(int incr)
{
char *stack_pointer;
asmv("mov r1, %0" : "=r" (stack_pointer));
stack_pointer -= STACK_EXTRA;
if(incr > (stack_pointer - cur_break))
return (void *)-1; /* ENOMEM */
void *old_break = cur_break;
cur_break += incr;
/*
* If the stack was never here then [old_break .. cur_break] should
* be filled with zeros.
*/
return old_break;
}
/*---------------------------------------------------------------------------*/
/*
* Mask all interrupts that can be masked.
*/
int
splhigh_(void)
{
/* Clear the GIE (General Interrupt Enable) flag. */
int sr;
asmv("mov r2, %0" : "=r" (sr));
asmv("bic %0, r2" : : "i" (GIE));
return sr & GIE; /* Ignore other sr bits. */
}
/*---------------------------------------------------------------------------*/
/*
* Restore previous interrupt mask.
*/
void
splx_(int sr)
{
/* If GIE was set, restore it. */
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++;
}
}
}
/*---------------------------------------------------------------------------*/