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No output coming from one of the LTDC pins of STM32F429

Question asked by kumar.anoop on Jan 25, 2016
Latest reply on Jan 25, 2016 by kumar.anoop
Hi ,
I have configured LTDC pins as follows.

/* Enable the LTDC and DMA2D clocks */
     __LTDC_CLK_ENABLE();
     __DMA2D_CLK_ENABLE();


     /* Enable GPIOs clock */
     LTDC_GPIO_CLK_EN;
     /*** LTDC Pins configuration ***/


     GPIO_Init_Structure.Mode      = GPIO_MODE_AF_PP;
     GPIO_Init_Structure.Pull      = GPIO_NOPULL;
     GPIO_Init_Structure.Speed     = GPIO_SPEED_FAST;
     GPIO_Init_Structure.Alternate = GPIO_AF14_LTDC;


     GPIO_Init_Structure.Pin       = LCD_DATA_PINS_1;
     HAL_GPIO_Init(LCD_DATA_PORT_1, &GPIO_Init_Structure);


     GPIO_Init_Structure.Pin       = LCD_DATA_PINS_2;
     HAL_GPIO_Init(LCD_DATA_PORT_2, &GPIO_Init_Structure);


     GPIO_Init_Structure.Pin       = LCD_DATA_PINS_3;
     HAL_GPIO_Init(LCD_DATA_PORT_3, &GPIO_Init_Structure);


     GPIO_Init_Structure.Pin       = LCD_DATA_PINS_4;
     HAL_GPIO_Init(LCD_DATA_PORT_4, &GPIO_Init_Structure);


     GPIO_Init_Structure.Pin       = LCD_DATA_PINS_5;
     HAL_GPIO_Init(LCD_DATA_PORT_5, &GPIO_Init_Structure);


     GPIO_Init_Structure.Pin                         =       LCD_HSYNC_PIN;
     HAL_GPIO_Init(LCD_HSYNC_PORT, &GPIO_Init_Structure);


     GPIO_Init_Structure.Pin                         =       LCD_VSYNC_PIN;
     HAL_GPIO_Init(LCD_VSYNC_PORT, &GPIO_Init_Structure);


     GPIO_Init_Structure.Pin                         =       LCD_MODE_PIN;
     HAL_GPIO_Init(LCD_MODE_PORT, &GPIO_Init_Structure);


     GPIO_Init_Structure.Pin                         =       LCD_CLK_PIN;
     HAL_GPIO_Init(LCD_CLK_PORT, &GPIO_Init_Structure);

But I found that in one of the pins, data is not coming properly when I checked in oscilloscope. 
(LCD_DATA_PINS_4)

#define LCD_DATA_PORT_4         GPIOB
#define LCD_DATA_PINS_4         GPIO_PIN_1
I tried to configure the same pins are GPIO and was able to change the pin conditions through debugger.

Why is this problem happening?
Is this because of the way I configured LTDC? 
Data signal is active in all the other pins . 
Connections are tested for continuity.

              


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