/*----------------------------------------------------------------------------
  initialize LCD Pins
 *----------------------------------------------------------------------------*/
void LCD_Initpins (void) {

  RCC->AHB1ENR    |=  ((1UL <<    3)  );   /* Enable GPIOD clock              */

  GPIOD->MODER    &= ~((3UL << 2* 0) |
                       (3UL << 2* 1) |
                       (3UL << 2* 2) |
                       (3UL << 2* 3) |
                       (3UL << 2* 4) |
                       (3UL << 2* 5) |
                       (3UL << 2* 6) |
                       (3UL << 2* 7)  );   /* PD.0..7 is output               */
  GPIOD->MODER    |=  ((1UL << 2* 0) |
                       (1UL << 2* 1) |
                       (1UL << 2* 2) |
                       (1UL << 2* 3) |
                       (1UL << 2* 4) |
                       (1UL << 2* 5) |
                       (1UL << 2* 6) |
                       (1UL << 2* 7)  );
  GPIOD->OTYPER   &= ~((1UL <<    0) |
                       (1UL <<    1) |
                       (1UL <<    2) |
                       (1UL <<    3) |
                       (1UL <<    4) |
                       (1UL <<    5) |
                       (1UL <<    6) |
                       (1UL <<    7)  );   /* PD.0..7 is output Push-Pull     */
  GPIOD->OSPEEDR  &= ~((3UL << 2* 0) |
                       (3UL << 2* 1) |
                       (3UL << 2* 2) |
                       (3UL << 2* 3) |
                       (3UL << 2* 4) |
                       (3UL << 2* 5) |
                       (3UL << 2* 6) |
                       (3UL << 2* 7)  );   /* PD.0..7 is 50MHz Fast Speed     */
  GPIOD->OSPEEDR  |=  ((2UL << 2* 0) |
                       (2UL << 2* 1) |
                       (2UL << 2* 2) |
                       (2UL << 2* 3) |
                       (2UL << 2* 4) |
                       (2UL << 2* 5) |
                       (2UL << 2* 6) |
                       (2UL << 2* 7)  );
  GPIOD->PUPDR    &= ~((3UL << 2* 0) |
                       (3UL << 2* 1) |
                       (3UL << 2* 2) |
                       (3UL << 2* 3) |
                       (3UL << 2* 4) |
                       (3UL << 2* 5) |
                       (3UL << 2* 6) |
                       (3UL << 2* 7)  );   /* PD.0..7 is Pull up              */
  GPIOD->PUPDR    |=  ((1UL << 2* 0) |
                       (1UL << 2* 1) |
                       (1UL << 2* 2) |
                       (1UL << 2* 3) |
                       (1UL << 2* 4) |
                       (1UL << 2* 5) |
                       (1UL << 2* 6) |
                       (1UL << 2* 7)  );


  // PORT B LCD Control Lines
  RCC->AHB1ENR    |=  ((1UL <<    1)  );   /* Enable GPIOB clock              */

  GPIOB->MODER    &= ~((3UL << 2* 0) |
                       (3UL << 2* 1) |
                       (3UL << 2* 2)  );   /* PB.0..7 is output               */
  GPIOB->MODER    |=  ((1UL << 2* 0) |
                       (1UL << 2* 1) |
                       (1UL << 2* 2)  );
  GPIOB->OTYPER   &= ~((1UL <<    0) |
                       (1UL <<    1) |
                       (1UL <<    2)  );   /* PB.0..7 is output Push-Pull     */
  GPIOB->OSPEEDR  &= ~((3UL << 2* 0) |
                       (3UL << 2* 1) |
                       (3UL << 2* 2)  );   /* PB.0..7 is 50MHz Fast Speed     */
  GPIOB->OSPEEDR  |=  ((2UL << 2* 0) |
                       (2UL << 2* 1) |
                       (2UL << 2* 2)  );
  GPIOB->PUPDR    &= ~((3UL << 2* 0) |
                       (3UL << 2* 1) |
                       (3UL << 2* 2)  );   /* PB.0..7 is Pull up              */
  GPIOB->PUPDR    |=  ((1UL << 2* 0) |
                       (1UL << 2* 1) |
                       (1UL << 2* 2)  );

  // PORT A LCD Driver IC Enable Line
  RCC->AHB1ENR    |=  ((1UL <<    0)  );   /* Enable GPIOA clock              */

  GPIOA->MODER    &= ~((3UL << 2*15)  );   /* PA.0..7 is output               */
  GPIOA->MODER    |=  ((1UL << 2*15)  );
  GPIOA->OTYPER   &= ~((1UL <<   15)  );   /* PA.15 is output Push-Pull     */
  GPIOA->OSPEEDR  &= ~((3UL << 2*15)  );   /* PA.15 is 50MHz Fast Speed     */
  GPIOA->OSPEEDR  |=  ((2UL << 2*15)  );
  GPIOA->PUPDR    &= ~((3UL << 2*15)  );   /* PA.15 is Pull up              */
  GPIOA->PUPDR    |=  ((1UL << 2*15)  );

}