[RA78K0] General

With the RA78K0, warning message

"W4301: Can't initialize RAM area 'fe20h − fe27h'"

is displayed.

The above message indicates that the program is described to locate an object in the RAM area (an area of FE20 to FE27 in this example) by a DB or DW pseudo instruction.

The DB and DW pseudo instructions are used to secure a part in the ROM area and set the initial values in this part.
They are not allowed to specify any part in the RAM area.
The DB and DW pseudo instruction thus cannot be described in the data segment (DSEG).

Use the DS pseudo instruction to set initial values in the RAM area. Describe a DS pseudo instruction in DSEG to secure a part in the RAM area, and then describe necessary instructions (e.g., MOV) in the code segment (CSEG) to set the initial values.

When you want to set constants to be used in the program, set them in the ROM area, not the RAM area.
In this case, describe a DB/DW pseudo instruction in CSEG.

-78K0-