M16C6NK Datasheet, PDF (88/404 Pages) Renesas Technology Corp – 16-BIT SINGLE-CHIP MICROCOMPUTER M16C FAMILY / M16C/60 SERIES

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M16C/6N Group (M16C/6NK, M16C/6NM)
8. Clock Generating Circuit
8.4.1.6 On-chip Oscillator Mode
The on-chip oscillator clock divided by 1 (undivided), 2, 4, 8 or 16 provides the CPU clock. The on-chip
oscillator clock is also the clock source for the peripheral function clocks. If the sub clock is activated,
fC32 can be used as the count source for timers A and B. When the operation mode is returned to the
high- and medium-speed modes, set the CM06 bit in the CM0 register to “1” (divide-by-8 mode).
8.4.1.7 On-chip Oscillator Low Power Dissipation Mode
The main clock is turned off after being placed in on-chip oscillator mode. The CPU clock can be
selected like in the on-chip oscillator mode. The on-chip oscillator clock is the clock source for the
peripheral function clocks. If the sub clock is activated, fC32 can be used as the count source for timers
A and B.
Table 8.3 lists the setting clock related bit and modes.
Table 8.3 Setting Clock Related Bit and Modes
Modes
CM2 Register CM1 Register
CM21
CM11 CM17, CM16 CM07
CM0 Register
CM06
CM05
CM04
PLL Operation Mode
0
1
00b
0
0
0
-
High-Speed Mode
0
0
00b
0
0
0
-
Medium- Divide-by-2
0
0
01b
0
0
0
-
Speed Divide-by-4
0
0
10b
0
0
0
-
Mode Divide-by-8
0
0
-
0
1
0
-
Divide-by-16
0
0
11b
0
0
0
-
Low-Speed Mode
-
0
-
1
-
0
1
Low Power
0
0
-
1
1 ⁽¹⁾
1 ⁽¹⁾
1
Dissipation Mode
On-chip Divide-by-1
1
0
00b
0
0
0
-
Oscillator Divide-by-2
1
0
01b
0
0
0
-
Mode Divide-by-4
1
0
10b
0
0
0
-
Divide-by-8
1
0
-
0
1
0
-
Divide-by-16
1
0
11b
0
0
0
-
On-chip Oscillator
1
0
(NOTE 2)
0
(NOTE 2)
1
-
Low power Dissipation
Mode
-: “0” or “1”
NOTES:
1. When the CM05 bit is set to “1” (main clock turned off) in low-speed mode, the mode goes to low power
dissipation mode and the CM06 bit is set to “1” (divide-by-8 mode) simultaneously.
2. The divide-by-n value can be selected the same way as in on-chip oscillator mode.
Rev.2.00 Nov 28, 2005 page 70 of 378
REJ09B0124-0200