Rom Mirroring Function Select Register (Romm) - Fujitsu F2MCTM-16LX Hardware Manual

CHAPTER 23 ROM MIRRORING MODULE
23.2

ROM Mirroring Function Select Register (ROMM)

The ROM mirroring function select register (ROMM) enables or disables the ROM
mirroring function. When the ROM mirroring function is enabled, ROM data in the FF
bank can be read by access to the 00 bank.
ROM Mirroring Function Select Register (ROMM)
Figure 23.2-1 ROM Mirroring Function Select Register (ROMM)
Address
15
00006F
H
W
X
Table 23.2-1 Functions of ROM Mirroring Function Select Register (ROMM)
bit8
bit9
to
bit15
Note:
While the ROM area at addresses "008000
function select register (ROMM) is prohibited.
528
14 13 12 11 10 9
: Write only
: Indeterminate
: Undefined
: Reset value
Bit Name
MI: This bit enables or disables the ROM mirroring function.
ROM mirroring When set to 0: Disables ROM mirroring function
function select bit When set to 1: Enables ROM mirroring function
• When the ROM mirroring function is enabled (MI = 1), data
at ROM addresses "FF8000
accessing addresses "008000
Undefined bits Read: Value is undefined.
Write: No effect
8
Reset value
MI
X X X X X X X 1
B
W
bit8
MI ROM mirroring function select bit
0 ROM mirroring function disabled
1 ROM mirroring function enabled
Function
" to "FFFFFF
H
" to "00FFFF
H
" to "00FFFF " is being used, access to the ROM mirroring
H H
" can be read by
H
".
H