Memory Map In Each Operating Mode; Reserved Areas - Hitachi H8/3008 Hardware Manual

3.6

Memory Map in Each Operating Mode

Figures 3.1 and 3.2 show memory maps of the H8/3008. In the expanded modes, the address space
is divided into eight areas.
The initial bus mode differs between modes 1 and 2, and also between modes 3 and 4.
The address locations of the on-chip RAM and on-chip registers differ between the 1-Mbyte
modes (modes 1 and 2) and the 16-Mbyte modes (modes 3 and 4). The address range specifiable
by the CPU in the 8- and 16-bit absolute addressing modes (@aa:8 and @aa:16) also differs.
3.6.1

Reserved Areas

The H8/3008 memory map includes reserved areas to which access (reading or writing) is
prohibited. Normal operation cannot be guaranteed if the following reserved areas are accessed.
Reserved Area in Internal I/O Register Space: The H8/3008 internal I/O register space includes
a reserved area to which access is prohibited. For details see Appendix B, Internal I/O Registers.
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