Core(M): Describe scatter file templates. (#1376)

* Core(M): Describe scatter file templates.

* Core(M): Describe scatter file templates.
- review changes.

CMSIS/DoxyGen/Core/src/Template.txt

@@ -194,6 +194,7 @@ The template files contain place holders:
 The device configuration of the template files is described in detail on the following pages:
   - \subpage startup_c_pg
   - \subpage startup_s_pg (deprecated)
+  - \subpage linker_sct_pg
   - \subpage system_c_pg
   - \subpage device_h_pg
 \if ARMv8M
@@ -377,6 +378,71 @@ The files for other compiler vendors differ slightly in the syntax, but not in t
 \verbinclude "Source/ARM/startup_Device_ac6.S"
 */
 
+/*=======0=========1=========2=========3=========4=========5=========6=========7=========8=========9=========0=========1====*/
+/**
+\page linker_sct_pg Scatter-Loading description file <device>_ac<5|6>.sct
+
+A scatter file for linking is required when using a \ref startup_c_pg "C startup file".
+
+The \ref linker_sct_pg contains regions for:
+ - Code (read-only data, execute-only data)
+ - RAM (read/write data, zero-initialized data)
+ - Stack
+ - Heap
+ - Stack seal (Armv8-M/v8.1-M)
+ - CMSE veneer (Armv8-M/v8.1-M)
+
+Within the scatter file, the user needs to specify a set of macros. The scatter file is passed through the
+C preprocessor which uses these macros to calculate the start address and the size of the different regions.
+
+\code
+/*--------------------- Flash Configuration ----------------------------------
+; <h> Flash Configuration
+;   <o0> Flash Base Address <0x0-0xFFFFFFFF:8>
+;   <o1> Flash Size (in Bytes) <0x0-0xFFFFFFFF:8>
+; </h>
+ *----------------------------------------------------------------------------*/
+#define __ROM_BASE      0x00000000
+#define __ROM_SIZE      0x00080000
+
+/*--------------------- Embedded RAM Configuration ---------------------------
+; <h> RAM Configuration
+;   <o0> RAM Base Address    <0x0-0xFFFFFFFF:8>
+;   <o1> RAM Size (in Bytes) <0x0-0xFFFFFFFF:8>
+; </h>
+ *----------------------------------------------------------------------------*/
+#define __RAM_BASE      0x20000000
+#define __RAM_SIZE      0x00040000
+
+/*--------------------- Stack / Heap Configuration ---------------------------
+; <h> Stack / Heap Configuration
+;   <o0> Stack Size (in Bytes) <0x0-0xFFFFFFFF:8>
+;   <o1> Heap Size (in Bytes) <0x0-0xFFFFFFFF:8>
+; </h>
+ *----------------------------------------------------------------------------*/
+#define __STACK_SIZE    0x00000200
+#define __HEAP_SIZE     0x00000C00
+
+/*--------------------- CMSE Venner Configuration ---------------------------
+; <h> CMSE Venner Configuration
+;   <o0>  CMSE Venner Size (in Bytes) <0x0-0xFFFFFFFF:32>
+; </h>
+ *----------------------------------------------------------------------------*/
+#define __CMSEVENEER_SIZE    0x200
+\endcode
+
+\note
+The stack is placed at the end of the available RAM and is growing downwards 
+whereas the Heap is placed after the application data and growing upwards.
+
+\section linker_sct_preproc_sec Preprocessor command
+The scatter file uses different preprocessor commands for Arm Compiler V6 and Arm Compiler V5
+ - \b AC6: #! armclang -E --target=arm-arm-none-eabi -mcpu=&lt;mcpu&gt; -xc
+ - \b AC5: #! armcc -E
+
+*/
+
+
 /*=======0=========1=========2=========3=========4=========5=========6=========7=========8=========9=========0=========1====*/
 /**
 \page system_c_pg System Configuration Files system_<device>.c and system_<device>.h