![](http://datasheet.mmic.net.cn/30000/MB90P553APF_datasheet_2367781/MB90P553APF_28.png)
MB90550A/550B Series
28
(Continued)
Initial value representations
0: Initial value of 0
1: Initial value of 1
X: Initial value undefined
_
: Initial value undefined (none)
Addresses that follow 00FFH are a reserved area.
The boundary #H between the RAM and reserved areas is different depending on each product.
Note : For writable bits, the initial value column contains the initial value to which the bit is initialized at a reset.
Notice that it is not the value read from the bit.
The LPMCR, CKSCR, and WDTC registers may be initialized or not at a reset, depending on the type of the
reset. Their initial values in the above list are those to which the registers are initialized, of course.
“R/W!” in the access column indicates that the register contains read-only or write-only bits.
If a read-modify-write instruction (such as a bit setting instruction) is used to access a register marked “R/
W!”, or “W” in the access column, the bit focused on by the instruction is set to the desired value but a
malfunction occurs if the other bits contains a write-only bit. Do not use such instructions to access those
registers.
Address
Register name
Abbreviated
register name
Read/write
Resource name
Initial value
1FF0H
Program address detection
register 0
PADR0
R/W
Address match
detection function
XXXXXXXX
1FF1H
Program address detection
register 1
R/W
XXXXXXXX
1FF2H
Program address detection
register 2
R/W
XXXXXXXX
1FF3H
Program address detection
register 3
PADR1
R/W
XXXXXXXX
1FF4H
Program address detection
register 4
R/W
XXXXXXXX
1FF5H
Program address detection
register 5
R/W
XXXXXXXX
1FF6H to
1FFFH
(Reserved area)