3858 Group
[CPU Mode Register (CPUM)] 003B16
The CPU mode register contains the stack page selection bit, etc.
The CPU mode register is allocated at address 003B16.
b7
b0
CPU mode register
1
(
CPUM : address 003B16)
Processor mode bits
b1 b0
0
0
1
1
0 : Single-chip mode
1 :
0 : Not available
1 :
Stack page selection bit
0 : 0 page
1 : 1 page
Fix this bit to “1”.
Port XC switch bit
0 : I/O port function (stop oscillating)
1 : XCIN–XCOUT oscillating function
Main clock (XIN–XOUT) stop bit
0 : Oscillating
1 : Stopped
Main clock division ratio selection bits
b7 b6
0
0
1
1
0 : φ = f(XIN)/2 (high-speed mode)
1 : φ = f(XIN)/8 (middle-speed mode)
0 : φ = f(XCIN)/2 (low-speed mode)
1 : Not available
Fig. 7 Structure of CPU mode register
Rev.1.10 Apr 3, 2006 page 9 of 75
REJ03B0139-0110
RENESAS [ RENESAS TECHNOLOGY CORP ]
