diff options
Diffstat (limited to 'board/snow/board.c')
| -rw-r--r-- | board/snow/board.c | 12 |
1 files changed, 10 insertions, 2 deletions
diff --git a/board/snow/board.c b/board/snow/board.c index b612955af3..258b534184 100644 --- a/board/snow/board.c +++ b/board/snow/board.c @@ -123,9 +123,17 @@ void configure_board(void) STM32_GPIO_BSRR_OFF(GPIO_B) |= (1<<11) | (1<<10) | (1<<7) | (1<<6); - /* Select Alternate function for USART1 on pins PA9/PA10 */ + /* + * Set alternate function for USART1. For alt. function input + * the port is configured in either floating or pull-up/down + * input mode (ref. section 7.1.4 in datasheet RM0041): + * PA9: Tx, alt. function output + * PA10: Rx, input with pull-down + * + * note: see crosbug.com/p/12223 for more info + */ val = STM32_GPIO_CRH_OFF(GPIO_A) & ~0x00000ff0; - val |= 0x00000990; + val |= 0x00000890; STM32_GPIO_CRH_OFF(GPIO_A) = val; /* EC_INT is output, open-drain */ |