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USART1 Remap not working: Influenced by I2C remap!

Question asked by mahipati.narayan.001 on May 10, 2014
Latest reply on May 10, 2014 by Clive One
I am having a strange problem where my UART1 remap is getting dependent on I2C1 remap.
Following is the scenario:
  • If I configure only UART1, remapped to PB6/7 it does not work
  • When I enable the remap for I2C1 along with UART1, UART1 starts working
Following is the snippet of my code:

  /* Configure USART Tx as alternate function push-pull */
  GPIO_InitStructure.GPIO_Pin = GPIO_Pin_6; 
  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;
  GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
  GPIO_Init(GPIOB, &GPIO_InitStructure);
  /* Configure USART Rx as input floating */
  GPIO_InitStructure.GPIO_Pin = GPIO_Pin_7;
  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN_FLOATING;
  GPIO_Init(GPIOB, &GPIO_InitStructure);
 //UART does not work without this remap!!!
   GPIO_PinRemapConfig(GPIO_Remap_I2C1, ENABLE);
 GPIO_PinRemapConfig(GPIO_Remap_USART1, ENABLE);

Please note that I have enabled the clocks for UART1, AFIO and PortB.
I am unable to understand why I have to enable the remap for I2C1! I am not using I2C1 and also tried by disabling the peripheral clock for I2C1, but in vain.

I appreciate any help regarding this issue. Thanks.

Note: I am also remapping CAN1 to PB8/9 which are shared by I2C1 also. I am not sure if this is affecting. CAN1 is working fine with remap.