README files. Don't ignore them.

[goodfet] / firmware / lib / msp430x1612.c

diff --git a/firmware/lib/msp430x1612.c b/firmware/lib/msp430x1612.c
new file mode 100644 (file)
index 0000000..e1d03a7
--- /dev/null
+++ b/firmware/lib/msp430x1612.c
@@ -0,0 +1,195 @@
+//! MSP430F1612/1611 clock and I/O definitions
+
+#include "platform.h"
+
+#include <signal.h>
+#include <io.h>
+#include <iomacros.h>
+
+
+//! Receive a byte.
+unsigned char serial_rx(){
+  char c;
+  
+  while(!(IFG1&URXIFG0));//wait for a byte
+  c = RXBUF0;
+  IFG1&=~URXIFG0;
+  U0TCTL &= ~URXSE;
+  
+  return c;
+}
+
+//! Receive a byte.
+unsigned char serial1_rx(){
+  char c;
+  
+  while(!(IFG2&URXIFG1));//wait for a byte
+  c = RXBUF1;
+  IFG2&=~URXIFG1;
+  U1TCTL &= ~URXSE;
+  
+  return c;
+}
+
+
+//! Transmit a byte.
+void serial_tx(unsigned char x){
+  while ((IFG1 & UTXIFG0) == 0); //loop until buffer is free
+  TXBUF0 = x;
+}
+
+//! Transmit a byte on the second UART.
+void serial1_tx(unsigned char x){
+  while ((IFG2 & UTXIFG1) == 0); //loop until buffer is free
+  TXBUF1 = x;
+}
+
+//! Set the baud rate.
+void setbaud(unsigned char rate){
+  
+  //http://mspgcc.sourceforge.net/baudrate.html
+  switch(rate){
+  case 1://9600 baud
+    UBR00=0x7F; UBR10=0x01; UMCTL0=0x5B; /* uart0 3683400Hz 9599bps */
+    break;
+  case 2://19200 baud
+    UBR00=0xBF; UBR10=0x00; UMCTL0=0xF7; /* uart0 3683400Hz 19194bps */
+    break;
+  case 3://38400 baud
+    UBR00=0x5F; UBR10=0x00; UMCTL0=0xBF; /* uart0 3683400Hz 38408bps */
+    break;
+  case 4://57600 baud
+    UBR00=0x40; UBR10=0x00; UMCTL0=0x00; /* uart0 3683400Hz 57553bps */
+    break;
+  default:
+  case 5://115200 baud
+    UBR00=0x20; UBR10=0x00; UMCTL0=0x00; /* uart0 3683400Hz 115106bps */
+    break;
+  }
+}
+
+//! Set the baud rate of the second uart.
+void setbaud1(unsigned char rate){
+  
+  //http://mspgcc.sourceforge.net/baudrate.html
+  switch(rate){
+  case 1://9600 baud
+    UBR01=0x7F; UBR11=0x01; UMCTL1=0x5B; /* uart0 3683400Hz 9599bps */
+    break;
+  case 2://19200 baud
+    UBR01=0xBF; UBR11=0x00; UMCTL1=0xF7; /* uart0 3683400Hz 19194bps */
+    break;
+  case 3://38400 baud
+    UBR01=0x5F; UBR11=0x00; UMCTL1=0xBF; /* uart0 3683400Hz 38408bps */
+    break;
+  case 4://57600 baud
+    UBR01=0x40; UBR11=0x00; UMCTL1=0x00; /* uart0 3683400Hz 57553bps */
+    break;
+  default:
+  case 5://115200 baud
+    UBR01=0x20; UBR11=0x00; UMCTL1=0x00; /* uart0 3683400Hz 115106bps */
+    break;
+  }
+}
+
+
+void msp430_init_uart(){
+  
+  P3SEL |= BIT4|BIT5;                        // P3.4,5 = USART0 TXD/RXD
+  P3DIR |= BIT4;
+  
+  UCTL0 = SWRST | CHAR;                 /* 8-bit character, UART mode */
+  UTCTL0 = SSEL1;                       /* UCLK = MCLK */
+  
+  setbaud(0);
+  
+  //Necessary for bit-banging, switch to hardware for performance.
+  ME1 &= ~USPIE0;                      /* USART1 SPI module disable */
+  ME1 |= (UTXE0 | URXE0);               /* Enable USART1 TXD/RXD */
+
+  UCTL0 &= ~SWRST;
+
+  /* XXX Clear pending interrupts before enable!!! */
+  U0TCTL |= URXSE;
+  
+  
+  //IE1 |= URXIE1;                        /* Enable USART1 RX interrupt  */
+}
+
+
+void msp430_init_dco() {
+    /* This code taken from the FU Berlin sources and reformatted. */
+  //
+
+//Works well.
+//#define MSP430_CPU_SPEED 2457600UL
+
+//Too fast for internal resistor.
+//#define MSP430_CPU_SPEED 4915200UL
+
+//Max speed.
+//#deefine MSP430_CPU_SPEED 4500000UL
+
+//baud rate speed
+#define MSP430_CPU_SPEED 3683400UL
+#define DELTA    ((MSP430_CPU_SPEED) / (32768 / 8))
+  unsigned int compare, oldcapture = 0;
+  unsigned int i;
+  
+  WDTCTL = WDTPW + WDTHOLD; //stop WDT
+  
+  
+  DCOCTL=0xF0;
+  //a4
+  //1100
+
+  /* ACLK is devided by 4. RSEL=6 no division for MCLK
+     and SSMCLK. XT2 is off. */
+  //BCSCTL1 = 0xa8;
+  
+  BCSCTL2 = 0x00; /* Init FLL to desired frequency using the 32762Hz
+                    crystal DCO frquenzy = 2,4576 MHz  */
+  
+  P1OUT|=1;
+  
+  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 */
+  
+  P1OUT=0;
+}
+