LPC43 Need to use fractional dividers to get the low-level UART BAUD correct

git-svn-id: svn://svn.code.sf.net/p/nuttx/code/trunk@4931 42af7a65-404d-4744-a932-0658087f49c3

1 files changed, 14 insertions, 0 deletions

diff --git a/nuttx/arch/arm/src/lpc43xx/lpc43_uart.h b/nuttx/arch/arm/src/lpc43xx/lpc43_uart.h
index 1eeafc20b..90216ff64 100644
--- a/nuttx/arch/arm/src/lpc43xx/lpc43_uart.h
+++ b/nuttx/arch/arm/src/lpc43xx/lpc43_uart.h
@@ -133,6 +133,20 @@ EXTERN void lpc43_usart2_setup(void);
 EXTERN void lpc43_usart3_setup(void);
 #endif
 
+/****************************************************************************
+ * Name: lpc43_setbaud
+ *
+ * Description:
+ *   Configure the U[S]ART divisors to accomplish the desired BAUD given the
+ *   U[S]ART base frequency.
+ *
+ *   This computationally intensive algorithm is based on the same logic
+ *   used in the NXP sample code.
+ *
+ ****************************************************************************/
+
+EXTERN void lpc43_setbaud(uintptr_t uartbase, uint32_t basefreq, uint32_t baud);
+
 #undef EXTERN
 #if defined(__cplusplus)
 }