Add usart_irq Code

1 files changed, 62 insertions, 0 deletions

diff --git a/libraries/fifo.h b/libraries/fifo.h
new file mode 100644
index 0000000..c56d410
--- /dev/null
+++ b/libraries/fifo.h
@@ -0,0 +1,62 @@
+
+
+/* 
+    FIFO Ring Buffer uint8_t array ring_buffer (example length is 8) 
+       with data (x) and read and write index:
+
+     --- --- --- --- --- --- --- ---
+    |   |   | x | x | x |   |   |   |
+     --- --- --- --- --- --- --- ---
+              ^           ^
+              |           |
+          read_index      |
+                     write_index
+
+     --- --- --- --- --- --- --- ---
+    | x | x |   |   |   | x | x | x |
+     --- --- --- --- --- --- --- ---
+              ^           ^
+              |           |
+         write_index      |
+                      read_index
+
+    - input data goes to position of write_index
+    - output data comes from read_index position
+    - after input/output operation the according index has to be modified
+    - according to the idea of ring buffers the write_index could be 
+      smaller than the read_index
+*/
+
+
+#ifndef FIFO_H
+#define FIFO_H
+
+
+#include <stdint.h>
+#include <stdlib.h>
+
+
+typedef struct FIFO{
+    uint8_t *buffer_ptr;
+    uint16_t read_index;
+    uint16_t write_index;
+    uint16_t bufferlength;
+} FIFO;
+
+
+void fifo_init(FIFO *fifo, uint16_t bufferlength);
+void fifo_deinit(FIFO *fifo);
+
+uint16_t fifo_get_buffersize(FIFO *fifo);
+
+uint16_t fifo_bytes_available(FIFO *fifo);
+uint16_t fifo_lines_available(FIFO *fifo);
+
+void fifo_move_read_index(FIFO *fifo);
+void fifo_move_write_index(FIFO *fifo);
+
+void fifo_get_byte(FIFO *fifo, uint8_t *data_sink);
+void fifo_put_byte(FIFO *fifo, uint8_t *data_source);
+
+
+#endif /* FIFO_H */