1 files changed, 75 insertions, 0 deletions
diff --git a/firmware/fifo.h b/firmware/fifo.h
new file mode 100644
index 0000000..32c3264
--- /dev/null
+++ b/firmware/fifo.h
@@ -0,0 +1,75 @@
+#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_ */
+