Reclocked to 3.6834 MHz, exactly twice a standard PC uart.

[goodfet] / firmware / lib / msp430f1612.c

diff --git a/firmware/lib/msp430f1612.c b/firmware/lib/msp430f1612.c
index c003213..c29a485 100644 (file)
--- a/firmware/lib/msp430f1612.c
+++ b/firmware/lib/msp430f1612.c
@@ -16,8 +16,6 @@ unsigned char serial_rx(){
   IFG1&=~URXIFG0;
   U0TCTL &= ~URXSE;
   
-  PLEDOUT^=PLEDPIN;
-  
   return c;
 }
 //! Transmit a byte.
@@ -26,6 +24,29 @@ void serial_tx(unsigned char x){
   TXBUF0 = 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;
+  }
+}
 
 void msp430_init_uart(){
   
@@ -34,14 +55,10 @@ 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 */
-
-  //http://mspgcc.sourceforge.net/baudrate.html
-  UBR00=0x00; UBR10=0x01; UMCTL0=0x00;
+  
+  setbaud(0);
   
   ME1 &= ~USPIE0;                      /* USART1 SPI module disable */
   ME1 |= (UTXE0 | URXE0);               /* Enable USART1 TXD/RXD */
@@ -50,26 +67,45 @@ void msp430_init_uart(){
 
   /* 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. */
-#define MSP430_CPU_SPEED 2457600UL
+  //
+
+//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
-
-  BCSCTL1 = 0xa4; /* ACLK is devided by 4. RSEL=6 no division for MCLK
+  
+  
+  DCOCTL=0xF0;
+  //a4
+  //1100
+  BCSCTL1 = 0xa8; /* 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  */
-
+  
+  P1OUT|=1;
+  
   BCSCTL1 |= DIVA1 + DIVA0;             /* ACLK = LFXT1CLK/8 */
   for(i = 0xffff; i > 0; i--) {         /* Delay for XTAL to settle */
     asm("nop");
@@ -102,10 +138,12 @@ void msp430_init_dco() {
                                         /* -> 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;
 }