
SINGLE-CHIP 8-BIT CMOS MICROCOMPUTER
MITSUBISHI MICROCOMPUTERS
3825 Group
14
[CPU Mode Register (CPUM)] 003B16
The CPU mode register contains the stack page selection bit and
the internal system clock selection bit.
The CPU mode register is allocated at address 003B
16.
Fig. 10 Structure of CPU mode register
o
t
a
v
a
a
e
rocessor mo
e
ts
b1 b0
0 0 : Single-chip mode
0 1 :
1 0 :
1 1 :
Stack page selection bit
0 : 0 page
1 : 1 page
Not used (returns “1” when read)
(Do not write “0” to this bit)
Port X
C switch bit
0 : I/O port function (stop oscillating)
1 : X
CIN–XCOUT oscillating function
Main clock (X
IN–XOUT) stop bit
0 : Oscillating
1 : Stopped
Main clock division ratio selection bit
0 : f(X
IN)/2 (high-speed mode)
1 : f(XIN)/8 (middle-speed mode)
Internal system clock selection bit
0 : X
IN–XOUT selected (middle-/high-speed mode)
1 : XCIN–XCOUT selected (low-speed mode)
mo
e reg
ster
:
a
r
e
s
s
0
0
3
1
6
7
0
Comentarios a estos manuales