Mode 4 (Expanded Maximum Mode):
Mode 4 supports a maximum 1-Mbyte address space of
which the first part is in on-chip ROM. Ports 1 to 6 are used for bus lines and bus control signals
as follows:
Control signals: Ports 1* and 2
Data bus:
Port 3
Address bus:
Ports 4, 5*, and 6*
* The functions of individual pins in ports 1, 5, and 6 are software-selectable.
Note:
In mode 4, ports 5 and 6 are initially general-purpose input ports. Software must change
them to output before using them for the address bus. See section 9.6, “Port 5” and 10.7, “Port 6”
for details. The following instruction sets all pins of ports 5 and 6 to output:
MOV.W #H'FFFF, @H'FE88
Mode 7 (Single-Chip Mode):
In this mode all memory is on-chip. It is not possible to access
off-chip addresses.
The single-chip mode provides the maximum number of ports. All the pins associated with the
address and data buses in the expanded modes are available as general-purpose input/output ports
in the single-chip mode.
2.3 Address Space Map
2.3.1 Page Segmentation
The address space is segmented into 64-kbyte pages. In the single-chip mode and expanded
minimum modes there is just one page: page 0. In the expanded maximum modes there can be
up to 16 pages. Figure 2-1 shows the address space of the H8/534 in each mode and indicates
which parts are on- and off-chip. Figure 2-2 shows the address space of the H8/536.
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