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/*
atmega88_example.c
*/
#ifndef F_CPU
#define F_CPU 8000000
#endif
#include <avr/io.h>
#include <stdio.h>
#include <avr/interrupt.h>
#include <avr/eeprom.h>
#include <avr/sleep.h>
/*
* This demonstrate how to use the avr_mcu_section.h file
* The macro adds a section to the ELF file with useful
* information for the simulator
*/
#include "avr_mcu_section.h"
AVR_MCU(F_CPU, "atmega88");
/*
* This small section tells simavr to generate a VCD trace dump with changes to these
* registers.
* Opening it with gtkwave will show you the data being pumped out into the data register
* UDR0, and the UDRE0 bit being set, then cleared
*/
const struct avr_mmcu_vcd_trace_t _mytrace[] _MMCU_ = {
{ AVR_MCU_VCD_SYMBOL("UDR0"), .what = (void*)&UDR0, },
{ AVR_MCU_VCD_SYMBOL("UDRE0"), .mask = (1 << UDRE0), .what = (void*)&UCSR0A, },
};
/* declare this in a .eeprom ELF section */
uint32_t value EEMEM = 0xdeadbeef;
static int uart_putchar(char c, FILE *stream) {
if (c == '\n')
uart_putchar('\r', stream);
loop_until_bit_is_set(UCSR0A, UDRE0);
UDR0 = c;
return 0;
}
static FILE mystdout = FDEV_SETUP_STREAM(uart_putchar, NULL,
_FDEV_SETUP_WRITE);
int main()
{
stdout = &mystdout;
// read the eeprom value
uint32_t c = eeprom_read_dword((void*)&value);
printf("Read from eeprom 0x%08lx -- should be 0xdeadbeef\n", c);
// change the eeprom
eeprom_write_dword((void*)&value, 0xcafef00d);
// re-read it
c = eeprom_read_dword((void*)&value);
printf("Read from eeprom 0x%08lx -- should be 0xcafef00d\n", c);
// this quits the simulator, since interupts are off
// this is a "feature" that allows running tests cases and exit
sleep_cpu();
}
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