how to use SDRAM in ugfx as buffer data

[laksonobufi]

hai friend... i need big data buffer for processing in stm32f746... i know it has 320kB sram... in discovery it has sdram external, and it use for framebuffer for lcd, how i can use it as memory data buffer? thankz

[inmarket]

As uGFX initializes the external RAM in the stm32746-discovery board file (and uses that for the framebuffer), any excess external RAM can be used by the application. You simply need to calculate the last address used by the framebuffer and use anything after that.

There is however one really big problem with this. Depending on the size of the display, whether you use both front and back display surfaces, the color depth you are using, and the refresh rate of the display, you may find that there is no available bus bandwidth available. Any reads/writes to the external RAM may cause display problems simply because the memory access prevents the display getting the data it needs.