Content originally posted in LPCWare by Bill@medsignals.com on Fri May 09 08:02:43 MST 2014
My program is using more than the 32k Ram that is in bank one and needs to utilize bank 2. However when I use the __DATA(RAM2) macro I encounter various problems depending on which variables I try to move to RAM2.
The project uses FreeRTOS with heap2, If I try to assign the heap to __DATA(RAM2) there are hard fault errors.
I recently found out that DMA (for i2s) is in use on this project. There are some buffers that are assigned as pointers to 0x2007d000 and the other is 0x2007e000. I don't like this hard coded assignment but when I try to use the __DATA(RAM2) macro to create buffers then use the address of these buffers, suddenly variables in RAM1 no longer work. In the memory view RAM1 is all zeros.
Can the AHB ram be used for both DMA and DATA?
Why do variables in RAM1 not get initialized properly when the __DATA(RAM2) macro is used anywhere in the project?
EDIT: If I change the buffers for the DMA to use __BSS(RAM2) suddenly everything seems to start working, Anyone know what would cause this?
