9. Memory Map
The H8/300L CPU supports two special memory areas, the 8-bit memory indirect addressing
area at addresses H'0000 to H'00FF and the 8-bit absolute addressing area at locations H'FF00
8-Bit Memory Indirect Addressing Area (Addresses H'0000 to H'00FF)
The H8/300L CPU uses the lowest locations in the ROM area as the interrupt vector table.
Since the details of the relationship between the interrupt vector table and the interrupts differ
for different products in the H8/300L Series, those details are described in the hardware
manual for each product. The H8/300L CPU supports the use of locations H'0000 to H'00FF,
which include the interrupt vector table, for indirect addressing with 8-bit addresses that are
included in the instruction code. This allows program sizes to be reduced by storing frequently
used branch addresses in this region.
Interrupt vector area
On-chip RAM area
On-chip I/O area
8-bit memory indirect addressing area
• This area can hold the effective
addresses for memory indirect
8-bit memory direct addressing area
• This area can be accessed by
2-byte data transfer instructions.