feat(ex04): done

ex04/include/uart.h

@@ -0,0 +1,29 @@
+#ifndef UART_H
+#define UART_H
+
+#include "mystd.h"
+
+void uart_init(void);
+
+void uart_tx(char data);
+void uart_sendstring(const char* str);
+
+void uart_send_u8(uint8_t val);
+void uart_send_u16(uint16_t val);
+void uart_send_u32(uint32_t val);
+
+
+void uart_send_i16(int16_t val);
+
+void uart_send_u8_hex(uint8_t val);
+void uart_send_u16_hex(uint16_t val);
+
+
+static inline void print_hex_value(char c)
+{
+	uart_send_u8_hex(c);
+}
+
+char uart_rx(void);
+
+#endif /* UART_H */