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| author | Kevin O'Connor <kevin@koconnor.net> | 2019-07-26 08:01:31 -0400 |
|---|---|---|
| committer | Kevin O'Connor <kevin@koconnor.net> | 2019-07-26 08:01:31 -0400 |
| commit | 899b6726fa0eada0253bccb72cab7c3b61274076 (patch) | |
| tree | 4ef136d45f55f3ac0dc7eff36a2787c546ed6a56 | |
| parent | f3d7287a282f205fd0914e35872b036b4c46ddf5 (diff) | |
| download | kutter-899b6726fa0eada0253bccb72cab7c3b61274076.tar.gz kutter-899b6726fa0eada0253bccb72cab7c3b61274076.tar.xz kutter-899b6726fa0eada0253bccb72cab7c3b61274076.zip | |
stm32f4: Improve serial baud rate calculation
Signed-off-by: Kevin O'Connor <kevin@koconnor.net>
| -rw-r--r-- | src/stm32f4/serial.c | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/src/stm32f4/serial.c b/src/stm32f4/serial.c index 951a8297..525e4493 100644 --- a/src/stm32f4/serial.c +++ b/src/stm32f4/serial.c @@ -21,8 +21,9 @@ serial_init(void) enable_pclock(USART2_BASE); uint32_t pclk = get_pclock_frequency(USART2_BASE); - uint32_t div = pclk / (CONFIG_SERIAL_BAUD * 16); - USART2->BRR = div << USART_BRR_DIV_Mantissa_Pos; + uint32_t div = DIV_ROUND_CLOSEST(pclk, CONFIG_SERIAL_BAUD); + USART2->BRR = (((div / 16) << USART_BRR_DIV_Mantissa_Pos) + | ((div % 16) << USART_BRR_DIV_Fraction_Pos)); USART2->CR1 = CR1_FLAGS; NVIC_SetPriority(USART2_IRQn, 0); NVIC_EnableIRQ(USART2_IRQn); |