MITSUBISHI MICROCOMPUTERS
3802 Group
SINGLE-CHIP 8-BIT CMOS MICROCOMPUTER
Memory
Special function register (SFR) area
The Special Function Register area in the zero page contains con-
trol registers such as I/O ports and timers.
Zero page
The 256 bytes from addresses 0000
16
to 00FF
16
are called the
zero page area. The internal RAM and the special function regis-
ters (SFR) are allocated to this area.
The zero page addressing mode can be used to specify memory
and register addresses in the zero page area. Access to this area
with only 2 bytes is possible in the zero page addressing mode.
RAM
RAM is used for data storage and for stack area of subroutine
calls and interrupts.
Special page
ROM
The first 128 bytes and the last 2 bytes of ROM are reserved for
device testing and the rest is user area for storing programs.
The 256 bytes from addresses FF00
16
to FFFF
16
are called the
special page area. The special page addressing mode can be
used to specify memory addresses in the special page area. Ac-
cess to this area with only 2 bytes is possible in the special page
addressing mode.
Interrupt vector area
The interrupt vector area contains reset and interrupt vectors.
RAM area
RAM capacity
(bytes)
Address
XXXX
16
0000
16
SFR area
0040
16
0100
16
Zero page
192
256
384
512
640
768
896
1024
00FF
16
013F
16
01BF
16
023F
16
02BF
16
033F
16
03BF
16
043F
16
RAM
XXXX
16
Reserved area
0440
16
ROM area
ROM capacity
(bytes)
Address
YYYY
16
Address
ZZZZ
16
Not used
YYYY
16
Reserved ROM area
(128 bytes)
4096
8192
12288
16384
20480
24576
28672
32768
F000
16
E000
16
D000
16
C000
16
B000
16
A000
16
9000
16
8000
16
F080
16
E080
16
D080
16
C080
16
B080
16
A080
16
9080
16
8080
16
ZZZZ
16
ROM
FF00
16
FFDC
16
Interrupt vector area
FFFE
16
FFFF
16
Special page
Reserved ROM area
Fig. 2 Memory map diagram
9
RENESAS [ RENESAS TECHNOLOGY CORP ]
