I am using Cold fire MCF52259 in our project.
I wanted to know the status of variables declared in RAM
during the Watch dog timer reset.
Will the variable restore its value on next power ON?
mjbcswitzerland gave link to excellent explanation for SRAM.
But, content of DRAM isn't guaranteed to be preserved due to suspending of the refresh.
Note, that the start-up code regularly include some memory test, which overwrites the SRAM or DRAM content.
I believe, any good start-up code has a few defines, which customize the behavior, including enable/disable memory test.
See the source code of your system start-up module. It's possible, that on-chip SRAM isn't tested at all.