![](http://datasheet.mmic.net.cn/330000/MB90F549_datasheet_16437915/MB90F549_19.png)
MB90540/545 Series
19
I
MEMORY SPACE
The memory space of the MB90540/545 Series is shown below.
The high-order portion of bank 00 gives the image of the FF bank ROM to make the small model of the C compiler
effective. Since the low-order 16 bits are the same, the table in ROM can be referenced without using the “far” spec-
ification in the pointer declaration.
For example, an attempt to access 00C000
H
accesses the value at FFC000
H
in ROM.The ROM area in bank FF
exceeds 48 Kbytes, and its entire image cannot be shown in bank 00.The image between FF4000
H
and FFFFFF
H
is visible in bank 00, while the image between FF0000
H
and FF3FFF
H
is visible only in bank FF.
MB90V540
MB90F543
MB90F549
FFFFFF
H
FF0000
H
FEFFFF
H
ROM
(FF bank)
FFFFFF
H
FF0000
H
FEFFFF
H
ROM
(FF bank)
FFFFFF
H
FF0000
H
FEFFFF
H
ROM
(FF bank)
FE0000
H
FDFFFF
H
ROM
(FE bank)
FE0000
H
ROM
(FE bank)
FE0000
H
FDFFFF
H
ROM
(FE bank)
FD0000
H
FCFFFF
H
ROM
(FD bank)
External
FD0000
H
FCFFFF
H
ROM
(FD bank)
FC0000
H
ROM
(FC bank)
FC0000
H
ROM
(FC bank)
External
External
00FFFF
H
004000
H
003FFF
H
ROM
(Image of FF
bank)
00FFFF
H
004000
H
003FFF
H
ROM
(Image of FF
bank)
00FFFF
H
004000
H
003FFF
H
ROM
(Image of FF
bank)
003900
H
Peripheral
003900
H
Peripheral
003900
H
Peripheral
External
002000
H
External
002000
H
External
0020FF
H
001FF5
H
001FF0
H
ROM correction
0018FF
H
000100
H
RAM 6K
0018FF
H
000100
H
RAM 6K
000100
H
RAM 8K
External
External
External
0000BF
H
000000
H
Peripheral
0000BF
H
000000
H
Peripheral
0000BF
H
000000
H
Peripheral