M16C Datasheet, PDF (39/262 Pages) Mitsubishi Electric Semiconductor – SINGLE-CHIP 16-BIT CMOS MICROCOMPUTER

Preliminary Specifications REV.B
Mitsubishi microcomputers
Specifications in this manual are tentative and subject to change.
M16C / 6N Group
SINGLE-CHIP 16-BIT CMOS MICROCOMPUTER
Clock Generating Circuit
A ring oscillator is built in the microcomputer. You can use it, instead of Xin, as a main clock by setup of the
bit 1 of the oscillation stop detect register. You can use it when for example at such a wait time as executing
confirmation of port value only. At this time, the frequency generated by the ring oscillator is low enough,
compared to Xin, to realize a low power consumption.
Clock Control
Figure 5-3 shows the block diagram of the clock generating circuit.
C01CLKR
b2 b1 b0
000a
001b
010c
011d
100e
fCAN0
C01CLKR
b6 b5 b4
000a
001b
010c
011d
100e
fCAN1
fCAN0
CM10 1
Write signal
RESET
Software reset
NMI
Interrupt request
level judgment
output
WAIT instruction
XCIN
CM04
XCOUT
Sub clock
SQ
XIN
R
Oscillation stop
detection circuit
XOUT
Main clock
Main clock
switching
circuit
Ring oscillator
CM02
SQ
CM05
R
1/32
fC32
fC
Selector
PCLK0=0
PCLK0=1
PCLK0=0
PCLK0=1
PCLK0=0
PCLK0=1
fCAN1
f2
f8
f32
f2AD
f2SIO2
f8SIO2
b c def
a _Divider g
f32SIO2
CM07=0
fC
CM07=1
Internal clock φ
b
c
d
e
f
a
1/2
1/2
1/2
1/2
1/2
CM06=1
CM06=0
CM17,CM16=10
CM06=0
CM17,CM16=11
g
CM0i : Bit i at address 000616
CM1i : Bit i at address 000716
WDCi : Bit i at address 000F16
CCLKi:Bit i at address 025F16
CM06=0
CM17,CM16=01
CM06=0
CM17,CM16=00
Details of divider
Figure 5-3. Clock generating circuit
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