Data Memory Area; Ram - Epson S1C63003 Technical Manual

3 CPu anD MeMORY
3.3

Data Memory area

The S1C63004/008/016 data memory consists of a RAM, data ROM, display memory and peripheral I/O memory.
The S1C63003 data memory consists of a RAM, display memory and peripheral I/O memory. Figure 3.3.1 shows
the overall memory map.
S1C63016
0000H

RAM

07FFH
Unused area
8000H
Data ROM
8FFFH
Unused area
F000H
Display memory area
F07FH
Unused area
FF00H
I/O memory area
FFFFH
4 bits
Note: Memory is not implemented in unused areas within the memory map. Further, some non-imple-
mentation areas and unused (access prohibition) areas exist in the peripheral I/O area. If the pro-
gram that accesses these areas is generated, its operation cannot be guaranteed. Refer to the I/O
memory maps in the Appendix for the peripheral I/O area.
3.3.1 RaM
The RAM is a data memory for storing various kinds of data.
Model
S1C63016
S1C63008
S1C63004
S1C63003
Addresses 0100H to 01FFH (0100H to 017FH in the S1C63003) are 4-bit/16-bit data accessible areas and in other
areas it is only possible to access 4-bit data. When programming, keep the following points in mind.
(1) Part of the RAM area is used as a stack area for subroutine call and register evacuation, so pay attention not to
overlap the data area and stack area.
(2) The S1C63000 core CPU handles the stack using the stack pointer for 4-bit data (SP2) and the stack pointer for
16-bit data (SP1). 16-bit data are accessed in stack handling by SP1, therefore, this stack area should be allocated
to the area where 4-bit/16-bit access is possible (0100H to 01FFH, 0100H to 017FH in the S1C63003). Memory
accesses except for stack operations by SP1 are 4-bit data access.
The stack address management requires caution as the stack pointers may be set to an address out of the RAM
address range.
3-2
S1C63008
0000H
RAM
03FFH
Unused area
8000H
Data ROM
87FFH
Unused area
F000H
Display memory area
F07FH
Unused area
FF00H
I/O memory area
FFFFH
4 bits
Figure 3. 3.1 Data memory map
Table 3. 3.1.1 RAM capacity
Capacity
2,048 words × 4 bits
1,024 words × 4 bits
512 words × 4 bits
256 words × 4 bits
Seiko epson Corporation
S1C63004
0000H
RAM
01FFH
Unused area
8000H
Data ROM
83FFH
Unused area
F000H
Display memory area
F07FH
Unused area
FF00H
I/O memory area
FFFFH
4 bits
Address
0000H to 07FFH
0000H to 03FFH
0000H to 01FFH
0000H to 007FH, 0100H to 017FH
S1C63003/004/008/016 TeChniCal Manual
S1C63003
0000H
RAM
007FH
Unused area
0100H
RAM
017FH
Unused area
F000H
Display memory area
F03FH
Unused area
FF00H
I/O memory area
FFFFH
4 bits
(Rev. 1.1)