M16C26A Datasheet, PDF (55/352 Pages) Renesas Technology Corp – 16-BIT SINGLE-CHIP MICROCOMPUTER M16C FAMILY / M16C/Tiny SERIES

M16C/26A Group (M16C/26A, M16C/26B, M16C/26T)
7. Clock Generation Circuit
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
Use of clock
Clock frequency
Main clock
oscillation circuit
Sub clock
oscillation circuit
On-chip oscillator
PLL frequency
synthesizer
• CPU clock source • CPU clock source • CPU clock source
• CPU clock source
• Peripheral function • Timer A, B's clock • Peripheral function clock source • Peripheral function clock
clock source
source
• CPU and peripheral function
source
clock sources when the main
clock stops oscillating
0 to 20 MHz
32.768 kHz
( ) • Selectable source frequency:
f1(ROC), f2(ROC), f3(ROC)
10 to 20 MHz
M16C/26A
M16C/26T
• Selectable divider:
by 2, by 4, by 8
10 to 24 MHz (M16C/26B)
Usable oscillator • Ceramic oscillator • Crystal oscillator
• Crystal oscillator
Pins to connect XIN, XOUT
oscillator
XCIN, XCOUT
Oscillation stop, Available
restart function
Available
( ) ^{Oscillator status}
after reset
Oscillating
M16C/26A
M16C/26B
Stopped
Stopped(M16C/26T)
Other
Externally derived clock can be input
Available
Oscillating
(CPU clock source)
Available
Stopped
Rev. 2.00 Feb.15, 2007 ^{page 38} of 329
REJ09B0202-0200