Bug in BSP_LCD_ReadPixel

[kuchura]

Posted on July 22, 2016 at 15:44

Hi,

Using CubeF7 with STM32F746G Discovery board.

Found a weird bug in

STM32Cube_FW_F7_V1.4.0\Drivers\BSP\STM32746G-Discovery\stm32746g_discovery_lcd.c

:

uint32_t BSP_LCD_ReadPixel(uint16_t Xpos, uint16_t Ypos)
{
uint32_t ret = 0;
if
(hLtdcHandler.LayerCfg[ActiveLayer].PixelFormat == LTDC_PIXEL_FORMAT_ARGB8888)
{
/* Read data value from SDRAM memory */
ret = *(__IO uint32_t*) (hLtdcHandler.LayerCfg[ActiveLayer].FBStartAdress + (2*(Ypos*BSP_LCD_GetXSize() + Xpos)));
}

The highlighted multiplier of

2

must be replaced with

4

, otherwise the code either returns data for the wrong pixel, or causes hardfault crash trying to access non-existing memory.

Similar changes probably should be made in the code below (for RGB888 format).

#!bug

[Imen.D]

Posted on December 21, 2016 at 16:56

Dear

‌

,

Thanks for highlighting this issue.

I confirmed this bug and it will be fixed in the coming versions.

Best Regards

Imen