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initial commit, compiles for ATTINY84 with TX on PA5 and RX on PA6

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juraj
2020-02-21 20:48:19 +01:00
commit 95ccf534a4
7 changed files with 400 additions and 0 deletions
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22
Makefile Normal file
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MCU=attiny84
CC=avr-gcc
LD=avr-ld
OBJCOPY=avr-objcopy
SIZE=avr-size
AVRDUDE=avrdude
CFLAGS=-Wall -g -Os -mmcu=${MCU} -I. -I..
TARGET=main
SRCS=main.c suart.c
all:
${CC} ${CFLAGS} -o ${TARGET}.o ${SRCS}
${LD} -o ${TARGET}.elf ${TARGET}.o
${OBJCOPY} -j .text -j .data -O ihex ${TARGET}.o ${TARGET}.hex
${SIZE} -C --mcu=${MCU} ${TARGET}.elf
flash:
${AVRDUDE} -p ${MCU} -c usbasp -U flash:w:${TARGET}.hex:i -F -P usb
clean:
rm -f *.c~ *.o *.elf *.hex

28
README Normal file
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soft-uart von rn-wissen.de, im Original fuer den ATMEGA8, abgeändert für ATTINY84 von juraj
Einstellungen werde in suart.c getätigt:
F_CPU ...für richtiges Timing
zB. 1000000
BAUDRATE ...
zB. 57600
---
SUART_TXD_PORT ...welches Register zu verwenden ist (SENDEN)
zB. PORTA
SUART_TXD_DDR ... --"-- (SENDEN)
zB. DDRA
SUART_TXD_BIT ... welcher Pin dieses Registers (SENDEN)
zB. PA5
---
SUART_RXD_PORT ...welches Register zu verwenden ist (EMPFANGEN)
zB. PORTA
SUART_RXD_PIN ... --"-- (EMPFANGEN)
zB. PINA
SUART_RXD_DDR ... --"-- (EMPFANGEN)
zB. DDRA
SUART_RXD_BIT ... welcher Pin dieses Registers (EMPFANGEN)
zB. PA6

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fifo.c Normal file
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#include "fifo.h"
void fifo_init (fifo_t *f, uint8_t *buffer, const uint8_t size)
{
f->count = 0;
f->pread = f->pwrite = buffer;
f->read2end = f->write2end = f->size = size;
}
uint8_t fifo_put (fifo_t *f, const uint8_t data)
{
return _inline_fifo_put (f, data);
}
uint8_t fifo_get_wait (fifo_t *f)
{
while (!f->count);
return _inline_fifo_get (f);
}
int fifo_get_nowait (fifo_t *f)
{
if (!f->count) return -1;
return (int) _inline_fifo_get (f);
}

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fifo.h Normal file
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#ifndef FIFO_H
#define FIFO_H
#include <avr/io.h>
#include <avr/interrupt.h>
typedef struct
{
uint8_t volatile count; // # Zeichen im Puffer
uint8_t size; // Puffer-Größe
uint8_t *pread; // Lesezeiger
uint8_t *pwrite; // Schreibzeiger
uint8_t read2end, write2end; // # Zeichen bis zum Überlauf Lese-/Schreibzeiger
} fifo_t;
extern void fifo_init (fifo_t*, uint8_t* buf, const uint8_t size);
extern uint8_t fifo_put (fifo_t*, const uint8_t data);
extern uint8_t fifo_get_wait (fifo_t*);
extern int fifo_get_nowait (fifo_t*);
static inline uint8_t
_inline_fifo_put (fifo_t *f, const uint8_t data)
{
if (f->count >= f->size)
return 0;
uint8_t * pwrite = f->pwrite;
*(pwrite++) = data;
uint8_t write2end = f->write2end;
if (--write2end == 0)
{
write2end = f->size;
pwrite -= write2end;
}
f->write2end = write2end;
f->pwrite = pwrite;
uint8_t sreg = SREG;
cli();
f->count++;
SREG = sreg;
return 1;
}
static inline uint8_t
_inline_fifo_get (fifo_t *f)
{
uint8_t *pread = f->pread;
uint8_t data = *(pread++);
uint8_t read2end = f->read2end;
if (--read2end == 0)
{
read2end = f->size;
pread -= read2end;
}
f->pread = pread;
f->read2end = read2end;
uint8_t sreg = SREG;
cli();
f->count--;
SREG = sreg;
return data;
}
#endif /* FIFO_H */

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main.c Normal file
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#define SUART_TXD
#define SUART_RXD
#include <avr/interrupt.h>
#include "suart.h"
int
main(void)
{
sei();
uart_init();
char c;
// not there yet, for now only echo
// uart_puts("Hello Parrot!\n");
while (1) {
c = uart_getc_wait();
uart_putc(c);
}
}

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suart.c Normal file
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#include <avr/io.h>
#include <avr/interrupt.h>
#ifndef SIGNAL
#include <avr/signal.h>
#endif // SIGNAL
#include "suart.h"
// Folgende Zeile einkommentieren, falls FIFO verwendet werden soll
#include "fifo.h"
#define F_CPU 1000000
#define BAUDRATE 38400
#define nop() __asm volatile ("nop")
#ifdef SUART_TXD
#define SUART_TXD_PORT PORTA
#define SUART_TXD_DDR DDRA
#define SUART_TXD_BIT PA5
static volatile uint16_t outframe;
#endif // SUART_TXD
#ifdef SUART_RXD
#define SUART_RXD_PORT PORTA
#define SUART_RXD_PIN PINA
#define SUART_RXD_DDR DDRA
#define SUART_RXD_BIT PA6
static volatile uint16_t inframe;
static volatile uint8_t inbits, received;
#ifdef _FIFO_H_
#define INBUF_SIZE 4
static uint8_t inbuf[INBUF_SIZE];
fifo_t infifo;
#else // _FIFO_H_
static volatile uint8_t indata;
#endif // _FIFO_H_
#endif // SUART_RXD
// Initialisierung für einen ATmega8
// Für andere AVR-Derivate sieht dies vermutlich anders aus:
// Registernamen ändern sich (zB TIMSK0 anstatt TIMSK, etc).
void uart_init()
{
uint8_t tifr = 0;
uint8_t sreg = SREG;
cli();
// Mode #4 für Timer1
// und volle MCU clock
// IC Noise Cancel
// IC on Falling Edge
TCCR1A = 0;
TCCR1B = (1 << WGM12) | (1 << CS10) | (0 << ICES1) | (1 << ICNC1);
// OutputCompare für gewünschte Timer1 Frequenz
OCR1A = (uint16_t) ((uint32_t) F_CPU/BAUDRATE);
#ifdef SUART_RXD
SUART_RXD_DDR &= ~(1 << SUART_RXD_BIT);
SUART_RXD_PORT |= (1 << SUART_RXD_BIT);
TIMSK0 |= (1 << ICIE1);
tifr |= (1 << ICF1) | (1 << OCF1B);
#else
TIMSK0 &= ~(1 << ICIE1);
#endif // SUART_RXD
#ifdef SUART_TXD
tifr |= (1 << OCF1A);
SUART_TXD_PORT |= (1 << SUART_TXD_BIT);
SUART_TXD_DDR |= (1 << SUART_TXD_BIT);
outframe = 0;
#endif // SUART_TXD
TIFR1 = tifr;
SREG = sreg;
#ifdef _FIFO_H_
fifo_init (&infifo, inbuf, INBUF_SIZE);
#endif // _FIFO_H_
}
// TRANSMITTER
#ifdef SUART_TXD
void uart_putc (const char c)
{
do
{
sei(); nop(); cli(); // yield();
} while (outframe);
// frame = *.P.7.6.5.4.3.2.1.0.S S=Start(0), P=Stop(1), *=Endemarke(1)
outframe = (3 << 9) | (((uint8_t) c) << 1);
TIMSK0 |= (1 << OCIE1A);
TIFR1 = (1 << OCF1A);
sei();
}
#endif // SUART_TXD
#ifdef SUART_TXD
SIGNAL (SIG_OUTPUT_COMPARE1A)
{
uint16_t data = outframe;
if (data & 1) SUART_TXD_PORT |= (1 << SUART_TXD_BIT);
else SUART_TXD_PORT &= ~(1 << SUART_TXD_BIT);
if (1 == data)
{
TIMSK0 &= ~(1 << OCIE1A);
}
outframe = data >> 1;
}
#endif // SUART_TXD
// RECEIVER
#ifdef SUART_RXD
SIGNAL (SIG_INPUT_CAPTURE1)
{
uint16_t icr1 = ICR1;
uint16_t ocr1a = OCR1A;
// Eine halbe Bitzeit zu ICR1 addieren (modulo OCR1A) und nach OCR1B
uint16_t ocr1b = icr1 + ocr1a/2;
if (ocr1b >= ocr1a)
ocr1b -= ocr1a;
OCR1B = ocr1b;
TIFR1 = (1 << OCF1B);
TIMSK0 = (TIMSK0 & ~(1 << ICIE1)) | (1 << OCIE1B);
inframe = 0;
inbits = 0;
}
#endif // SUART_RXD
#ifdef SUART_RXD
SIGNAL (SIG_OUTPUT_COMPARE1B)
{
uint16_t data = inframe >> 1;
if (SUART_RXD_PIN & (1 << SUART_RXD_BIT))
data |= (1 << 9);
uint8_t bits = inbits+1;
if (10 == bits)
{
if ((data & 1) == 0)
if (data >= (1 << 9))
{
#ifdef _FIFO_H_
_inline_fifo_put (&infifo, data >> 1);
#else
indata = data >> 1;
#endif // _FIFO_H_
received = 1;
}
TIMSK0 = (TIMSK0 & ~(1 << OCIE1B)) | (1 << ICIE1);
TIFR1 = (1 << ICF1);
}
else
{
inbits = bits;
inframe = data;
}
}
#endif // SUART_RXD
#ifdef SUART_RXD
#ifdef _FIFO_H_
int uart_getc_wait()
{
return (int) fifo_get_wait (&infifo);
}
int uart_getc_nowait()
{
return fifo_get_nowait (&infifo);
}
#else // _FIFO_H_
int uart_getc_wait()
{
while (!received) {}
received = 0;
return (int) indata;
}
int uart_getc_nowait()
{
if (received)
{
received = 0;
return (int) indata;
}
return -1;
}
#endif // _FIFO_H_
#endif // SUART_RXD

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suart.h Normal file
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#ifndef _UART_H_
#define _UART_H_
#define SUART_TXD
#define SUART_RXD
extern void uart_init();
#ifdef SUART_TXD
extern void uart_putc (const char);
#endif // SUART_RXD
#ifdef SUART_RXD
extern int uart_getc_wait ();
extern int uart_getc_nowait();
#endif // SUART_RXD
#endif /* _UART_H_ */