STM32F469 datasheet(16/91 Pages) STMICROELECTRONICS

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Overview of LTDC controller and STM32 MCUs graphical portfolio

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LTDC in a smart architecture

The LTDC is a master on the AHB architecture which performs read access on internal and

external memories. The LTDC has two independent layers, each one with its own FIFO

enabling more flexibility of the display.

The LTDC controller autonomously fetches graphical data at the speed of the AHB bus from

the framebuffer. The graphical data is then stored in one of the FIFO internal layers then

driven to the display.

The system architecture enables that graphics can be built and plotted to the screen without

any CPU intervention. The LTDC retrieves the data belonging to an image from the

framebuffer, while the Chrom-Art Accelerator® (DMA2D) is preparing the next images.

The LTDC interface is integrated in a smart architecture allowing:

•

LTDC autonomously fetches the graphical data from the framebuffer (can be internal

memories such as internal Flash, internal SRAM or external memories such as

FMC_SDRAM or Quad-SPI) and drives it to the display.

•

DMA2D as an AHB master can be used to offload the CPU from graphics intensive

tasks.

•

LTDC is able to continue displaying graphics even in sleep mode when the CPU is not

running.

•

The multi-layer AHB bus architecture improves memories throughput and leads to

higher performance.

System architecture on STM32F429/439 and STM32F469/479 microcontrollers

The system architecture of the STM32F429/439 line and the STM32F469/479 line consists

mainly of 32-bit multilayer AHB bus matrix that interconnects ten masters and nine slaves

(eight slaves for the STM32F429/F439). The LTDC is one of the ten AHB masters on the

AHB busmatrix.

The LTDC can autonomously access all the memory slaves on the AHB bus matrix, such as

FLASH, SRAM1, SRAM2, SRAM3 FMC or Quad-SPI enabling an efficient data transfer

which is ideal for graphical applications. Figure 9 shows the LTDC interconnection in the

STM32F429/439 and STM32F469/479 lines systems.

STM32F469 Datasheet(PDF) 16 Page - STMicroelectronics