
S1C88348/317/316/308 TECHNICAL HARDWARE
EPSON
I-15
3 CPU AND BUS CONFIGURATION
3 CPU AND BUS CONFIGURATION
In this section, we will explain the CPU, operating mode and bus configuration.
3.1 CPU
The S1C883xx utilize the S1C88 8-bit core CPU
whose resistor configuration, command set, etc. are
virtually identical to other units in the family of
processors incorporating the S1C88.
See the "S1C88 Core CPU Manual" for the S1C88.
Specifically, the S1C883xx employ the Model 3
S1C88 CPU which has a maximum address space of
512K bytes
× 4.
3.2 Internal Memory
The S1C883xx is equipped with internal ROM and
RAM as shown in Figure 3.2.1. Small scale applica-
tions can be handled by one chip. It is also possible
to utilize internal memory in combination with
external memory.
Furthermore, internal ROM can be disconnected
from the bus and the resulting space released for
external applications.
3.2.1 ROM
The internal ROM capacity is shown in Table
3.2.1.1.
Table 3.2.1.1 Internal ROM capacity
The ROM areas shown above can be released to
external memory depending on the setting of the
MCU/MPU terminal. (See "3.5 Chip Mode".)
3.2.2 RAM
The internal RAM capacity is shown in Table
3.2.2.1.
Table 3.2.2.1 Internal RAM capacity
Even when external memory which overlaps the
internal RAM area is expanded, the RAM area is
not released to external memory. Access to this area
is via internal RAM.
3.2.3 I/O memory
A memory mapped I/O method is employed in the
S1C883xx for interfacing with internal peripheral
circuit. Peripheral circuit control bits and data
register are arranged in data memory space.
Control and data exchange are conducted via
normal memory access. I/O memory is arranged in
page 0: 00FF00H–00FFFFH area.
See Section 5.1, "I/O Memory Map", for details of
the I/O memory.
Even when external memory which overlaps the I/O
memory area is expanded, the I/O memory area is
not released to external memory. Access to this area
is via I/O memory.
Model
S1C88348
S1C88317
S1C88316
S1C88308
Address
000000H–00BFFFH
000000H–003FFFH
000000H–001FFFH
ROM capacity
48K bytes
16K bytes
8K bytes
Model
S1C88348
S1C88317
S1C88316
S1C88308
Address
00F000H–00F7FFH
00F000H–00F0FFH
RAM capacity
2K bytes
256 bytes
00FFFFH
00FF00H
00FD42H
00F800H
00F7FFH
00F000H
00EFFFH
:
00C000H
00BFFFH
004000H
003FFFH
002000H
001FFFH
000000H
S1C88348
I/O memory
Display memory
RAM (2K bytes)
Undefined
area
ROM
(48K bytes)
S1C88317/316
I/O memory
Display memory
RAM (2K bytes)
Undefined
area
ROM
(16K bytes)
00F0FFH
S1C88308
I/O memory
Display memory
RAM (256 bytes)
Undefined
area
ROM
(8K bytes)
Fig. 3.2.1 Internal memory map