How to access external memory on MPC5554

[gracep21]

Hello! I am currently working on running some basic algorithms on an MPC5554 but I am having trouble figuring out how to make use of the external SRAM. For now, all my algorithms only run on internal memory. 

[davidtosenovjan]

If you are using PeMicro debugger (that is part of CodeWarrior) it work as is, because initialization script

mpc5500_vle.mac

or

mpc5500_booke.mac

has already initialized EBI.

CodeWarrior stationery also has EBI initialization code in file MPC5554_HWInit.c. AT default only internal flash calls that initialization.

Also you have to modify the code at the beginning of the file from NO_EXTERNAL_MEMORY to MPC5554DEMO_AXM_0321:

/* Used board */

//#define INIT_USED_BOARD NO_EXTERNAL_MEMORY

#define INIT_USED_BOARD MPC5554DEMO_AXM_0321

And check SRAM_SEL jumper whether you selected the right chip select.

SRAM is mapped from address 0x2000_0000.

Let me know if further assistance is needed.