Subversion Repositories softavrcore

#define         F_CPU           12000000UL

#include <avr/cpufunc.h>

#include <avr/interrupt.h>

#include <inttypes.h>

#include <util/delay.h>

#include <stdio.h>

/*****************************************************************************/

#define         __IOR(x)        (*(volatile uint8_t *)(0x20+(x)))

#define         __IOW(x)        (*(volatile uint16_t *)(0x20+(x)))

/*****************************************************************************/

#define         IO_BASE_UART0           0x00

#define         IO_BASE_PORTOUT0        0x04

#define         IO_BASE_TIMER0          0x08

/* uart.h */

#define         UDR0            __IOR(IO_BASE_UART0+0x00)

#define         UCSRA0          __IOR(IO_BASE_UART0+0x01)

#define         UCSRB0          __IOR(IO_BASE_UART0+0x02)

#define         UBRR0           __IOR(IO_BASE_UART0+0x03)

/* UCSRA */

#define         RXB8            0

#define         PE              2

#define         DOR             3

#define         FE              4

#define         UDRE            5

#define         TXC             6

#define         RXC             7

/* UCSRB */

#define         TXB8            0

#define         UCSZ            1

#define         UPM0            2

#define         UPM1            3

#define         USBS            4

#define         UDRIE           5

#define         TXCIE           6

#define         RXCIE           7       

/* timer.h */

#define         TCNT0           __IOW(IO_BASE_TIMER0+0x00)

#define         TCR0            __IOR(IO_BASE_TIMER0+0x02)

#define         TSR0            __IOR(IO_BASE_TIMER0+0x03)

#define         TOF             7       /* timer overflow */

#define         TOFIE           7       /* timer overflow interrupt enable */

#define         TPRESC0         0        /* timer prescaler bit 0 */

#define         TPRESC1         1       /* timer prescaler bit 1 */

/* port.h */

#define         PORTOUT0        __IOR(IO_BASE_PORTOUT0+0x00)

/*****************************************************************************/

static int uart_putchar(char c, FILE *stream)

{

 loop_until_bit_is_set(UCSRA0, UDRE);

 UDR0 = c;

 return(0);

}

static FILE mystdout = FDEV_SETUP_STREAM(uart_putchar, NULL, _FDEV_SETUP_WRITE);

/*****************************************************************************/

/* RXC */

ISR(_VECTOR(3))

{

 uint8_t        c;

 c=UDR0;

 if ( 'a' <= c && c <= 'z' )     c-=('a'-'A');

 UDR0=c;

}

ISR(_VECTOR(1))

{

 TCR0=TCR0;

 PORTOUT0 ^= 0x02;

}

static inline void msleep(uint16_t msec)

{

 while ( msec )

  {     _delay_loop_2((uint32_t)F_CPU/4000UL);

        msec--;

  }

}

static void test_memory_buffer(void)

{

 static char *  string="0123456789";

 uint8_t        length=10,offset,cnt;

 msleep(10);

 offset=0;

 cnt=0;

 while ( 1 )

  {     uint8_t c;

        while ( ! (UCSRA0&(1<<RXC)) );

        c=UDR0;

        if ( c != 10 )

         {      c=string[offset];

                offset++;

                if ( length==offset )   offset=0;

         }

        UDR0=c;

        cnt++;

        PORTOUT0=cnt&3;

  };

}

static void test_uppercase(void)

{

 while ( 1 )

  {     uint8_t c;

        while ( ! (UCSRA0&(1<<RXC)) );

        c=UDR0;

        if ( 'a' <= c && c <= 'z' )     c-=('a'-'A');

        while ( ! (UCSRA0&(1<<UDRE)) );

        UDR0=c;

  };

}

static void test_printf(void)

{

 int    i;

 stdout=&mystdout;

 i=0;

 PORTOUT0 = 0x90;

 PORTOUT0 ^= 0x03;

 while ( 1 )

  {     PORTOUT0 ^= 0x03;

        printf("[x] %d => %d\n",i,i*i);

        msleep(1000);

        i++;

  }

}

void test_interrupt(void)

{

 UCSRB0 |= (1<<RXCIE);

 TCR0 = 0x02;

 TCR0 |= (1<<TOFIE);

 sei();

 while ( 1 )

  {     PORTOUT0 ^= 0x01;

        msleep(500);

  }

}

int main(void)

{

 uint8_t        c;

 UBRR0 = 13-1;

 test_printf();

 test_interrupt();

 test_uppercase();

 test_memory_buffer();

 c=0;

 while ( 1 )

  {     msleep(500);

        PORTOUT0=c;

        UDR0='a'+c;

        c=(c+1)%4;

  }

 test_uppercase();

 return(0);

}