CSCI E-92: Application Note 22

CodeWarrior Segment Sizes
-------------------------

Within our K70FN1M0 chip, we have 1M byte of program Flash and we have
128K bytes of static RAM.

The addresses used to access this on-chip RAM are defined in the K70
Sub-Family Reference Manual, Rev. 4, Oct-2015 in Chapter 4: Memory
Map.  Table 4-1: System memory map on labeled page 199 (PDF page 206)
for our Cortex-M4 core (M1) shows that,

SRAM_L: Lower SRAM (ICODE/DCODE) for all masters is at addresses
0x1C00_0000-0x1FFF_FFFF

SRAM_U: Upper SRAM (ICODE/DCODE) for all masters is at addresses
0x2000_0000-0x200F_FFFF

For our K70FN1M0, the 128K bytes of static RAM is split equally
between SRAM_L and SRAM_U.  So, SRAM_L is at addresses
0x1FFF_0000-0x1FFF_FFFF and SRAM_U is at addresses
0x2000_0000-0x2000_FFFF.  Therefore, in the K70, the address just past
the end of RAM is 0x2001_0000.

In CodeWarrior, the allocation of available RAM among the interrupt
vector table, text, and data segments is defined in the
MK70FN1M0_ram.ld file in the Linker_Files folder for each project.
(Remember that the text segment is where code resides and the data
segment is where data resides.)

The initial configuration is,

/* Specify the memory areas */
MEMORY
{
  m_interrupts	(rx) : ORIGIN = 0x1FFF0000, LENGTH = 0x1E8
  m_text 	(rx) : ORIGIN = 0x1FFF01E8, LENGTH = 64K-0x1E8	/* Lower SRAM */
  m_data 	(rw) : ORIGIN = 0x20000000, LENGTH = 64K	/* Upper SRAM */
}

The initial stack pointer is 0x2001_0000 -- just past the highest RAM
address.  The heap size is 0x800 and the stack size is 0x800.  The
heap is located just below the stack in memory.

The above initial configuration has 64K-0x1E8 bytes for text and 64K
bytes for data.

It is possible change the amount of RAM available for the text and
data segments by appropriately changing this file.