This processor is Big Endian. If we push rD=1234h on the stack starting at 1BFh, we would get the following
[01BE]=12 <-SP at end of operation [01BF]=34
Stack pointer points to the last byte written and is decreased. Usually it is placed at or near the top of RAM.
Info provided by 3p141592654 working with 7M D151802 ECU.