Table of Contents
Advertisement
M
1
6
C
2 /
6
A
G
o r
u
p
(
M
1
7. Clock Generation Circuit
The clock generation circuit contains four oscillator circuits as follows:
(1) Main clock oscillation circuit
(2) Sub clock oscillation circuit
(3) On-chip oscillator (available at reset, oscillation stop detect function)
(4) PLL frequency synthesizer
Table 7.1 lists the clock generation circuit specifications. Figure 7.1 shows the clock generation circuit.
Figures 7.2 to 7.6 show the clock-related registers.
Table 7.1. Clock Generation Circuit Specifications
Item
oscillation circuit
• CPU clock source
Use of clock
• Peripheral function
clock source
Clock frequency
0 to 20 MHz
• Ceramic oscillator
Usable oscillator
• Crystal oscillator
X
Pins to connect
IN
oscillator
Available
Oscillation stop,
restart function
Oscillator status
Oscillating
after reset
Stopped(M16C/26T)
Other
Externally derived clock can be input
R
e
. v
2
0 .
0
F
e
b
1 .
, 5
2
0
0
7
R
E
J
0
9
B
0
2
0
2
0 -
2
0
0
6
C
2 /
6
, A
M
1
6
C
2 /
6
, B
M
1
Main clock
Sub clock
oscillation circuit
• CPU clock source
• Timer A, B's clock
source
32.768 kHz
• Crystal oscillator
, X
X
, X
OUT
CIN
COUT
Available
(
)
M16C/26A
Stopped
M16C/26B
page 38
f o
3
2
9
6
C
2 /
6
) T
On-chip oscillator
• CPU clock source
• Peripheral function clock source
• CPU and peripheral function
clock sources when the main
clock stops oscillating
• Selectable source frequency:
f
1(ROC)
• Selectable divider:
by 2, by 4, by 8
Available
Oscillating
(CPU clock source)
7. Clock Generation Circuit
PLL frequency
synthesizer
• CPU clock source
• Peripheral function clock
source
10 to 20 MHz
, f
, f
2(ROC)
3(ROC)
10 to 24 MHz (M16C/26B)
Available
Stopped
M16C/26A
(
)
M16C/26T
Advertisement
Table of Contents
