diff options
| -rw-r--r-- | os/hal/platforms/AVR/serial_lld.h | 22 | ||||
| -rw-r--r-- | readme.txt | 2 |
2 files changed, 23 insertions, 1 deletions
diff --git a/os/hal/platforms/AVR/serial_lld.h b/os/hal/platforms/AVR/serial_lld.h index c383b6c70..bcaea51c1 100644 --- a/os/hal/platforms/AVR/serial_lld.h +++ b/os/hal/platforms/AVR/serial_lld.h @@ -106,7 +106,27 @@ typedef struct { * @brief Macro for baud rate computation.
* @note Make sure the final baud rate is within tolerance.
*/
-#define UBRR(b) (((F_CPU / b) >> 4) - 1)
+#define UBRR(b) (((F_CPU / b) >> 4) - 1)
+
+/**
+ * @brief Macro for baud rate computationwhen U2Xn == 1.
+ * @note Make sure the final baud rate is within tolerance.
+ */
+#define UBRR2(b) (((F_CPU / b) >> 3) - 1)
+
+/**
+* @brief Macro for baud rate computation.
+* @note Make sure the final baud rate is within tolerance.
+* @note This version uses floating point math for greater accuracy.
+*/
+#define UBRR_F(b) ((((double) F_CPU / (double) b) / 16.0) - 0.5)
+
+/**
+* @brief Macro for baud rate computation when U2Xn == 1.
+* @note Make sure the final baud rate is within tolerance.
+* @note This version uses floating point math for greater accuracy.
+*/
+#define UBRR2_F(b) ((((double) F_CPU / (double) b) / 8.0) - 0.5)
/*===========================================================================*/
/* External declarations. */
diff --git a/readme.txt b/readme.txt index 8a6a42644..2e057664c 100644 --- a/readme.txt +++ b/readme.txt @@ -79,6 +79,8 @@ *** 2.5.0 ***
- NEW: Updated debug plugin 1.0.8 (backported to 2.4.0).
+- NEW: Added more accurate UBRR calculation in AVR serial driver (backported
+ to 2.4.0).
*** 2.3.5 ***
- FIX: Fixed RTC compile problem on STM32F103 (bug 3468445).
|