779
21.3
Operation
When the RAME bit is set to 1, accesses to addresses H'FFB000 to H'FFEFBF and H'FFFFC0 to
H'FFFFFF in the H8S/2633, to addresses H'FFC000 to H'FFEFBF and H'FFFFC0 to H'FFFFFF in
the H8S/2632, and to addresses H'FFD000 to H'FFEFBF and H'FFFFC0 to H'FFFFFF in the
H8S/2631, are directed to the on-chip RAM. When the RAME bit is cleared to 0, the off-chip
address space is accessed.
Since the on-chip RAM is connected to the CPU by an internal 16-bit data bus, it can be written to
and read in byte or word units. Each type of access can be performed in one state.
Even addresses use the upper 8 bits, and odd addresses use the lower 8 bits. Word data must start
at an even address.
21.4
Usage Notes
When Using the DTC: DTC register information can be located in addresses H'FFEBC0 to
H'FFEFBF. When the DTC is used, the RAME bit must not be cleared to 0.
Reserved Areas: Addresses H'FFB000 to H'FFBFFF in the H8S/2632, and H'FFB000 to
H'FFCFFF in the H8S/2631 are reserved areas that cannot be read or written to. When the RAME
bit is cleared to 0, the off-chip address space is accessed.
Содержание H8S/2631
Страница 28: ...xviii Appendix G Package Dimensions 1154 ...
Страница 341: ...316 Transfer SAR or DAR DAR or SAR Block area First block Nth block Figure 9 8 Memory Mapping in Block Transfer Mode ...
Страница 918: ...905 ø DREQ0 DREQ1 tDRQS tDRQH Figure 25 19 DMAC DREQ Input Timing ...
Страница 955: ...943 A 2 Instruction Codes Table A 2 shows the instruction codes ...