Renesas H8/38024 Hardware Manual page 174

Note: *
The output data is not guaranteed if this address area is read in PROM mode.
Therefore, when programming with a PROM programmer, be sure to specify
addresses from H'0000 to H'7FFF. If programming is inadvertently performed from
H'8000 onward, it may not be possible to continue PROM programming and
verification.
When programming, H'FF should be set as the data in this address area (H'8000 to
H'1FFFF).
Rev. 6.00, 08/04, page 144 of 628
Address in
MCU mode
H'0000
H'7FFF
Figure 6.3 H8/38024 Memory Map in PROM Mode
Address in
PROM mode
On-chip PROM
Uninstalled area *
H'0000
H'7FFF
H'1FFFF