
10
EPSON
S1C8F360 TECHNICAL MANUAL
3 CPU AND BUS CONFIGURATION
s Expanded 64K mode (MPU mode)
The expanded 64K mode setting applies when
the S1C8F360 is used with 64K bytes or less of
external expanded memory. This mode is only
usable on the MPU mode setting. When the
S1C8F360 is started in the MPU mode, the
expanded 64K mode is set after an initial reset.
Since the internal PROM area is released in the
MPU mode, external memory in this model can
be assigned to the area from 000000H to
00EFFFH. The area from 00F000H to 00FFFFH is
assigned to internal memory (RAM, etc.) and
cannot be used to access an external device.
This mode setting is suitable for small- to mid-
scale systems. The address range of the chip
_____
enable (CE) signal, adapted to memory chips
with a capacity of from 8 to 64K bytes, can be
selected in software to any one of four settings.
_____
See Section 3.6.4, "Chip enable (CE) signal", for
_____
the CE signal.
CPU operation in this mode is equivalent to the
S1C88 core CPU Model 3 minimum mode. The
area within physical space 000000H to 00FFFFH
is only effective as a target for accessing.
00FFFFH
00F000H
00EFFFH
000000H
See Figure 3.2.1 for the internal memory
- MPU mode -
Internal memory
External
memory area
Fig. 3.5.2.2 Memory map for the expanded
64K mode (MPU mode)
s Expanded 512K minimum mode
The expanded 512K minimum mode setting
applies when the S1C8F360 is used with over
64K bytes and less than 512K bytes
× 4 of
external expanded memory. This mode is
usable regardless of the MCU/MPU mode
setting.
Because internal PROM is being used in the
MCU mode, external memory in this model can
be assigned to the area from 080000H to
27FFFFH.
Since the internal PROM area is released in the
MPU mode, external memory in this model can be
assigned to the area from 000000H to 1FFFFFH.
3.5.2 Bus mode
In order to set bus specifications to match the
configuration of external expanded memory, four
different bus modes described below are selectable
in software.
s Single chip mode
Fig. 3.5.2.1 Memory map for the single chip mode
The single chip mode setting applies when the
S1C8F360 is used as a single chip microcom-
puter without external expanded memory.
Since this mode employs internal PROM, the
system can only be operated in the MCU mode
discussed in Section 3.5.1. In the MPU mode, the
system cannot be set to the single chip mode.
Since there is no need for an external bus line in
this mode, terminals normally set for bus use
can be used as general purpose output ports or
I/O ports.
Accordingly, the output ports are in a 34-bit
configuration in the S1C8F360 and the I/O ports
are in a 16-bit configuration.
CPU operation in this mode is equivalent to the
S1C88 core CPU Model 3 minimum mode.
Addresses assigned to internal memory within
physical space 000000H to 00FFFFH are only
effective as a target for accessing.
00FFFFH
00FF00H
00FD42H
00F800H
00F7FFH
00F000H
00EFFFH
000000H
- MCU mode -
I/O memory
Display memory
Internal RAM
Internal PROM