User guide spru514 section 2.3.4 entry for --unified_memory needs updates to clarify impact of using volatile.

The wording in above section could use more details for distinguishing source vs destination operands of struct assigns.

Struct assigns from non-volatile to volatile can use RPT with PREAD which uses the program bus for reading the non-volatile source operand:

RPT #4

Struct assigns from volatile to non-volatile can use RPT with PWRITE which uses the program bus for writing to the non-volatile destination operand:

RPT #4