I-20
EPSON
S1C88348/317/316/308 TECHNICAL HARDWARE
3 CPU AND BUS CONFIGURATION
s Expanded 512K maximum mode
The expanded 512K maximum mode setting
applies when the S1C883xx 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 ROM is being used in the MCU
mode, external memory can be assigned to the
area from 080000H to 27FFFFH.
Since the internal ROM area is released in the
MPU mode, external memory can be assigned
to the area from 000000H to 1FFFFFH.
The area from 00F000H to 00FFFFH is assigned
to internal memory and cannot be used to
access an external device.
CPU operation in this mode is equivalent to the
S1C88 core CPU Model 3 maximum mode, the
area within physical space 000000H to 1FFFFFH
in the MPU mode or physical space 080000H to
27FFFFH + internal memory in the MCU mode
is effective as a target for accessing. In the above
mentioned physical space, since program
memory and data memory can be secured with
an optional (maximum 512K bytes
× 4 program
+ data) size, this mode is suitable for systems
with large-scale program and data capacity.
The address range of chip enable (CE) signals in
this mode is fixed at 512K bytes.
Fig. 3.5.2.4 Memory map for the expanded 512K maximum mode
There is an explanation on how all these settings are actually made in "5.2 System Controller and Bus
Control" of this Manual.
S1C88308
- MCU mode -
27FFFFH
:
080000H
07FFFFH
010000H
00FFFFH
00F000H
00EFFFH
:
00C000H
00BFFFH
004000H
003FFFH
002000H
001FFFH
000000H
See Figure 3.2.1 for the internal memory
- MPU mode -
External
memory area
Internal memory
External
memory area
External
memory area
Internal memory
Unused area
Internal memory
1FFFFFH
S1C88317/316
- MCU mode -
External
memory area
Internal memory
Unused area
Internal memory
Unused area
S1C88348
- MCU mode -
External
memory area
Internal memory
Unused area
Internal memory
Unused area