M16C6S_09 Datasheet, PDF (42/208 Pages) Renesas Technology Corp – SINGLE-CHIP 16-BIT CMOS MICROCOMPUTER

M16C/6S Group
Clock Generation Circuit
Main clock oscillation
High-speed mode
CPU clock: f(XIN)
CM07=0
CM06=0
CM17=0
CM16=0
Middle-speed mode Middle-speed mode
(divide by 2)
(divide by 4)
CPU clock: f(XIN)/2
CM07=0
CM06=0
CM17=0
CM16=1
CPU clock: f(XIN)/4
CM07=0
CM06=0
CM17=1
CM16=0
Middle-speed mode Middle-speed mode
(divide by 8)
(divide by 16)
CPU clock: f(XIN)/8
CM07=0
CM06=1
CPU clock: f(XIN)/16
CM07=0
CM06=0
CM17=1
CM16=1
(Note 2)
On-chip Oscillator
clock oscillation
On-chip Oscillator mode
CM21=0
(Note 4)
CM21=1
CPU clock
f(Ring)
f(Ring)/2
f(Ring)/4
f(Ring)/8
f(Ring)/16
(Note 3)
Notes:
1: Avoid making a transition when the CM20 bit in the CM2 register is set to “1” (oscillation stop, re-oscillation detection function enabled).
Set the CM20 bit to “0” (oscillation stop, re-oscillation detection function disabled) before transiting.
2: Change CM17 and CM16 bits in the CM1 register before changing CM06 bit in the CM0 register.
3: Transit in accordance with arrow.
4: Set the CM06 to “1” (division by 8 mode) before changing back the operation mode from on-chip oscillator mode to high- or middle-speed mode.
Figure 1.7.8. State Transition in Normal Mode
Rev.5.01 Dec 10, 2009 page 42 of 201
REJ03B0014-0501