MB90340E Series
30
DS07-13747-4E
Note: An image of the data in the FF bank of ROM is visible in the upper part of bank 00, which makes it possible
for the C compiler to use the small memory model. The lower 16 bits of addresses in the FF bank are the
same as the lower 16 bits of addresses in the 00 bank so that tables stored in the ROM can be accessed
without using the far specifier in the pointer declaration.
For example, when the address 00C000H is accessed, the data at FFC000H in ROM is actually accessed.
The ROM area in bank FF exceeds 32 Kbytes, and its entire image cannot be shown in bank 00.
As a result, the image between FF8000H and FFFFFFH is visible in bank 00, while the image between FF0000H
and FF7FFFH is visible only in bank FF.
MB90342E(S)/342CE(S)
MB90F342E(S)/F342CE(S)
MB90349E(S)/349CE(S)
MB90F349E(S)/F349CE(S)
MB90341E(S)/341CE(S)
MB90348E(S)/348CE(S)
MB90347E(S)/347CE(S)
MB90F347E(S)/F347CE(S)
MB90346E(S)/346CE(S)
MB90F346E(S)/F346CE(S)
FFFFFFH
FF0000H
FEFFFFH
FE0000H
FDFFFFH
FD0000H
FCFFFFH
FC0000H
0000EFH
000000H
00FFFFH
007FFFH
007900H
003FFFH
000100H
008000H
FFFFFFH
FF0000H
FEFFFFH
FE0000H
0000EFH
000000H
00FFFFH
007FFFH
007900H
003FFFH
000100H
008000H
FFFFFFH
FF0000H
FEFFFFH
FE0000H
0000EFH
000000H
00FFFFH
007FFFH
007900H
0018FFH
000100H
008000H
FFFFFFH
FF0000H
FEFFFFH
FE0000H
0000EFH
000000H
00FFFFH
007FFFH
007900H
0008FFH
000100H
008000H
ROM (FF bank)
ROM (FE bank)
ROM (FD bank)
ROM (FC bank)
External
access area
ROM (image
of FF bank)
Peripheral
RAM 16 Kbytes
External access area
Peripheral
: Not accessible
External
access area
ROM (image
of FF bank)
Peripheral
RAM 16 Kbytes
External access area
Peripheral
External
access area
ROM (image
of FF bank)
Peripheral
RAM 6 Kbytes
External access area
Peripheral
External
access area
ROM (image
of FF bank)
Peripheral
RAM 2 Kbytes
External access area
Peripheral
ROM (FF bank)
ROM (FE bank)
ROM (FF bank)
ROM (FE bank)
ROM (FF bank)