3804H_M Datasheet, PDF (264/387 Pages) Renesas Technology Corp – 8-BIT CISC SINGLE-CHIP MICROCOMPUTER 740 FAMILY / 38000 SERIES

3804 Group (Spec.H)
APPLICATION
2.9 Watchdog timer
CPU mode register
b7 b6 b5 b4 b3 b2 b1 b0
1
CPU mode register
(CPUM: address 003B16)
b
Name
0 Processor mode
bits
1
2 Stack page
selection bit
3 Fix this bit to “1”.
Functions
b1 b0
00 : Single-chip mode
01 :
10 : Not available
11 :
0 : 0 page
1 : 1 page
4 ^{Port Xc switch bit}
0: I/O port function
(stop oscillating)
1: XCIN-XCOUT oscillation
function
5 ^{Main clock (XIN-}
XOUT) stop bit
6 ^{Main clock division}
ratio selection bits
7
0: Oscillating
1: Stopped
b7 b6
0 0: φ=f(XIN)/2
(high-speed mode)
0 1: φ=f(XIN)/8
(middle-speed mode)
1 0: φ=f(XCIN)/2
(low-speed mode)
1 1: Not available
At reset R W
0
0
0
1
0
0
1
0
Fig. 2.9.3 Structure of CPU mode register
Rev.1.00 Jan 14, 2005
REJ09B0212-0100Z
2-140