MB90480/485 Series
■ MEMORY MAP
• MB90F481/F482/487B/488B/483C/F488B/V480/V485B/F489B
Internal ROM
external bus
External ROM
external bus
Single chip
ROM area
FFFFFF
H
ROM area
Address #1
010000
H
ROM area
ROM area
FF bank image
FF bank image
Address #2
Address #3
✽
Register
Register
RAM
Register
RAM
RAM
000100
0000D0
H
H
Peripheral
Peripheral
Peripheral
000000
H
: Internal
* : In models where address #3 overlaps with address #2, this external area does not exist.
: External
: Access inhibited
Model
Address #1
FC0000H *1
FC0000H
Address #2
Address #3
001100H
001900H
002900H
002900H
002900H
004000H
004000H
004000H
006100H*3
MB90F481
MB90F482
MB90487B
MB90488B
MB90F488B
MB90V480
MB90V485B
MB90483C
MB90F489B
FD0000H
004000H or 008000H,
selected by the MS bit in
the ROMM register
FC0000H
FC0000H
(FC0000H)
(FC0000H)
FB0000H*4
F90000H *2
0080000H fixed
*1 : No memory cells from FC0000H to FC7FFFH and FE0000H to FE7FFFH.
The upper part of the 00 bank is set up to mirror the image of FF bank ROM, to enable efficient use of small
model C compilers. Because the lower 16-bit address of the FF bank and the lower 16-bit address of the 00
bank are the same, enabling reference to tables in ROM without using the for specification in the pointer
declaration.
For example, in accessing address 00C000H it is actually the contents of ROM at FFC000H that are accessed.
If the MS bit in the ROMM register is set to “0”, the ROM area in the FF bank will exceed 48 Kbytes and it is
not possible to reflect the entire area in the image in the 00 bank. Therefore the image from FF4000H to FFFFFFH
is reflected in the 00 bank and the area from FF0000H to FF3FFFH can be seen in the FF bank only.
(Continued)
19
FUJITSU [ FUJITSU ]
