M16C65 Datasheet, PDF (185/829 Pages) Renesas Technology Corp – RENESAS MCU M16C FAMILY / M16C/60

Under development
M16C/65 Group
Preliminary Specification
This is a preliminary specification and is subject to change.
9. Power Control
9.6 Notes on Power Control
9.6.1 CPU Clock
• When switching clock sources of the CPU clock, wait until the clock oscillation switched to is
stabilized.
9.6.2 Wait Mode
• After the WAIT instruction, insert at least four NOP instructions. When entering wait mode, the
instruction queue reads ahead the instructions following WAIT. Thus, depending on timing, some of
the instructions may be executed before the MCU enters wait mode.
Program example when entering wait mode is shown below.
Program Example:
FSET
WAIT
NOP
NOP
NOP
NOP
I;
; Enter wait mode
; More than four NOP instructions
• Do not enter wait mode when the FMR23 bit in the FMR2 register is 1 (low current consumption
read mode enabled). Set the FMR23 bit to 0 (low current consumption read mode disabled) and
the FMR01 bit to 0 (CPU rewrite mode disabled), and disable DMA transfer before entering wait
mode.
REJ09B0484-0030 Rev.0.30 Sep 09, 2008
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