M32C8A Datasheet, PDF (103/372 Pages) Renesas Technology Corp – RENESAS MCU M16C FAMILY / M32C/80 Series

M32C/8A Group
9. Clock Generation Circuits
9.5.1.1 Main Clock Mode
The main clock divided by 1 (no division), 2, 3, 4, 6, 8, 10, 12, 14, or 16 is used as the source for the CPU clock.
The main clock is also used as the source for fPFC. When the sub clock is running, fC32 can be used as the
count source for timer A and timer B.
9.5.1.2 PLL Mode
The PLL clock divided by 1 (no division), 2, 3, 4, 6, 8, 10, 12, 14, or 16 is used as the source for the CPU clock.
The PLL clock is also used as the source for fPFC. When the sub clock is running, fC32 can be used as the
count source for timer A and timer B.
9.5.1.3 Low-Speed Mode
The sub clock is used as the source for the CPU clock. The main clock, PLL clock, or on-chip oscillator clock is
used as the source for fPFC. fC32 can be used as the count source for timer A and timer B.
9.5.1.4 Low-Power Consumption Mode
The MCU enters low-power consumption mode when the main clock stops in low-speed mode. The sub clock is
used as the source for the CPU clock, and the on-chip oscillator clock is used as the source for fPFC. fC32 can
be used as the count source for timer A and timer B. In low-power consumption mode, bits MCD4 to MCD0 in
the MCD register become 01000b (divide-by-8 mode). Therefore, next time the CPU clock source is switched
to the main clock, the CPU clock is the main clock divided by eight.
9.5.1.5 On-Chip Oscillator Mode
The on-chip oscillator clock divided by 1 (no division), 2, 3, 4, 6, 8, 10, 12, 14, or 16 is used as the source for
the CPU clock. The on-chip oscillator clock is also used as the source for fPFC. When the sub clock is running,
fC32 can be used as the count source for timer A and timer B.
9.5.1.6 On-Chip Oscillator Low-power Consumption Mode
The MCU enters on-chip oscillator low-power consumption mode when the main clock stops in on-chip
oscillator mode. The on-chip oscillator clock divided by 1 (no division), 2, 3, 4, 6, 8, 10, 12, 14, or 16 is used as
the source for the CPU clock. The on-chip oscillator clock is also used as the source for fPFC. When the sub
clock is running, fC32 can be used as the count source for timer A and timer B.
Rev.1.00 Jul 15, 2007 Page 86 of 352
REJ09B0385-0100