Put stack and some data to CCMRAM

CPU can access this data independently without stalling DMA transfers

Author: tikonen

STM32F407VGTx_FLASH.ld

@@ -53,7 +53,8 @@
 ENTRY(Reset_Handler)
 
 /* Highest address of the user mode stack */
-_estack = 0x20020000;    /* end of RAM */
+/*_estack = 0x20020000;*/    /* end of RAM */
+_estack = 0x10010000; /* end of CCRAM */
 /* Generate a link error if heap and stack don't fit into RAM */
 _Min_Heap_Size = 0x200;      /* required amount of heap  */
 _Min_Stack_Size = 0x400; /* required amount of stack */
@@ -191,7 +192,7 @@ SECTIONS
     . = . + _Min_Heap_Size;
     . = . + _Min_Stack_Size;
     . = ALIGN(8);
-  } >RAM
+  } >CCMRAM 
 
 
 

Src/usbd_audio_if.c

@@ -478,7 +478,7 @@ struct AudioCommand
 	uint32_t count;
 	uint8_t sync;
 	uint8_t cmd;
-} audioCommands[2];
+} audioCommands[2] __attribute__((section(".ccmram")));
 uint8_t cmdReadIdx = 0;
 uint8_t cmdWriteIdx = 0;