initial merge of donbfet code, sans changes to monitor/avr/spi

[goodfet] / firmware / lib / atmega1284p.c

diff --git a/firmware/lib/atmega1284p.c b/firmware/lib/atmega1284p.c
new file mode 100644 (file)
index 0000000..2199ecf
--- /dev/null
+++ b/firmware/lib/atmega1284p.c
@@ -0,0 +1,173 @@
+#include "platform.h"
+
+#include <avr/io.h>
+#include <util/delay.h>
+
+//! Receive a byte.
+unsigned char serial0_rx(){
+  while( !(UCSR0A & (1 << RXC0)) );
+  return UDR0;
+}
+
+//! Receive a byte.
+unsigned char serial1_rx(){
+  return 0;
+}
+
+//! Transmit a byte.
+void serial0_tx(unsigned char x){
+  while (!(UCSR0A & (1<<UDRE0)) );
+  UDR0 = x;
+}
+
+//! Transmit a byte on the second UART.
+void serial1_tx(unsigned char x){
+}
+
+//! Set the baud rate.
+void setbaud0(unsigned char rate){
+        /* disable briefly */
+        UCSR0B = 0;
+
+        UBRR0L = 4;   /* 500,000 baud at 20MHz */
+        //UBRR0L = 1;   /* 500,000 baud at 8MHz */
+        //UBRR0L = 103; /* 9600 baud */
+        // XXX UBRR0L = 8;     /* 115200 baud ERROR RATE TOO HIGH */
+        UBRR0H = 0;
+
+        UCSR0A = (1 << U2X0);   /* double the baud rate */
+        UCSR0C = (3 << UCSZ00); /* 8N1 */
+
+        /* enabling rx/tx must be done after frame/baud setup */
+        UCSR0B = ((1 << TXEN0) | (1 << RXEN0));
+
+  return;
+  
+}
+
+//! 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
+    
+    break;
+  case 2://19200 baud
+    
+    break;
+  case 3://38400 baud
+    
+    break;
+  case 4://57600 baud
+    
+    break;
+  default:
+  case 5://115200 baud
+    
+    break;
+  }
+}
+
+
+void donbfet_init_uart0(){
+  setbaud0(0);
+  _delay_ms(500); //takes a bit to stabilize
+}
+
+void 
+led_on()
+{
+       PLEDOUT |= (1 << PLEDPIN);
+}
+
+void
+led_off()
+{
+       PLEDOUT &= ~(1 << PLEDPIN);
+}
+
+void 
+donbfet_init()
+{
+        uint8_t x;
+
+        /* explicitly clear interrupts */
+        cli();
+
+        /* move the vectors */
+
+        /* move interrupts from boot flash section */
+        /* NB */
+        /* you MUST use a variable during this process. even highly optimized,
+         * masking the bit, shifting, ANDing, and setting MCUCR will exceed
+         * 4 CPU cycles! set a variable with the desired value for MCUCR and
+         * then set the register once IVCE is enabled
+         */
+        x = MCUCR & ~(1 << IVSEL);
+
+        /* enable change of interrupt vectors */
+        /* NOTE: setting IVCE disables interrupts until the bit is auto-unset 
+         * 4 cycles after being set or after IVSEL is written
+         */
+        MCUCR |= (1 << IVCE);
+        MCUCR = x;
+
+        /* disable the watchdog timer; this macro will disable interrupts for us */
+        /* NOTE: ensure that the WDRF flag is unset in the MCUSR or we will spinlock
+         * when the watchdog times out
+         */
+        MCUSR &= ~(1 << WDRF);
+        wdt_disable();
+
+        /* init the USART */
+        donbfet_init_uart0();
+
+       /* set the LED as an output */
+       PLEDDIR |= (1 << PLEDPIN);
+       PLEDOUT |= (1 << PLEDPIN);
+
+        /* explicitly enable interrupts */
+        sei();
+}
+
+void
+donbfet_reboot()
+{
+       MCUSR &= ~(1 << WDRF);
+       wdt_enable(WDTO_15MS);
+       while(1)
+               _delay_ms(127);
+}
+
+void donbfet_init_uart1(){
+}
+
+uint8_t
+donbfet_get_byte(uint16_t v)
+{
+       /* NB */
+       /* we are only passed in a 16bit word. should 
+        * be increased to 32bit if we want to handle
+        * far reads as well
+        */
+/* XXX should be far on the 1284P, but there are bugs with flash reads using _far */
+/* XXX until the bugs are figured out (probably my fault?) use _near */
+       return pgm_read_byte_near(v);
+}
+
+int * 
+donbfet_ramend(void)
+{
+       /* NB */
+       /* ATmega1284P has 16K SRAM */
+       return (int * )0x4000; 
+}
+
+void
+led_toggle(void)
+{
+       led_on();
+       _delay_ms(30);
+       led_off();
+}
+