STM32 LCD interfacing

LCD Tutorial 1.c

/*
NOTE: This code had a bug which I edited in the browser to fix.  UNTESTED.

Code to set up 8 pins for output to an LCD display.

This code sets up the 8 pins and turns on Port C, 6

#NEWBIEHACK

RL 03-01-2022

*/

  // Set up GPIO Port B
  RCC->AHBENR |= RCC_AHBENR_GPIOBEN;
  // Set mode for GPIOB pins
  GPIOB->MODER = 0;
  GPIOB->MODER |=
	    0b01 << GPIO_MODER_MODER12_Pos
	  | 0b01 << GPIO_MODER_MODER13_Pos
	  | 0b01 << GPIO_MODER_MODER14_Pos
	  | 0b01 << GPIO_MODER_MODER15_Pos;

  GPIOB->OTYPER = 0;

  GPIOB->OSPEEDR = 0;
  GPIOB->OSPEEDR |= 
	  0b11 << GPIO_OSPEEDR_OSPEEDR12_Pos
	| 0b11 << GPIO_OSPEEDR_OSPEEDR13_Pos
	| 0b11 << GPIO_OSPEEDR_OSPEEDR14_Pos
	| 0b11 << GPIO_OSPEEDR_OSPEEDR15_Pos;

  GPIOB->PUPDR = 0 ;

  // Set u GPIO Port C
  RCC->AHBENR |= RCC_AHBENR_GPIOCEN;
  // Set mode for GPIO-C pins
  GPIOC->MODER = 0;
  GPIOC->MODER |=
	    0b01 << GPIO_MODER_MODER6_Pos
	  | 0b01 << GPIO_MODER_MODER7_Pos
	  | 0b01 << GPIO_MODER_MODER8_Pos
	  | 0b01 << GPIO_MODER_MODER9_Pos;

  GPIOC->OTYPER = 0;

  GPIOC->OSPEEDR = 0;
  GPIOC->OSPEEDR |=
	0b11 << GPIO_OSPEEDR_OSPEEDR6_Pos
      | 0b11 << GPIO_OSPEEDR_OSPEEDR7_Pos
      | 0b11 << GPIO_OSPEEDR_OSPEEDR8_Pos
      | 0b11 << GPIO_OSPEEDR_OSPEEDR9_Pos;

  GPIOC->PUPDR = 0 ;

  // Turn on Port C, Pin 6
  GPIOC->BSRR |= GPIO_BSRR_BS_6;