M32C8A Datasheet, PDF (105/372 Pages) Renesas Technology Corp – RENESAS MCU M16C FAMILY / M32C/80 Series

M32C/8A Group
9. Clock Generation Circuits
Start
(1) Initial setting
RLVL register: bits RLVL2 to RLVL0 = 7
Set an interrupt priority level of each interrupt
(2) Before entering wait mode
I flag = 0
Set the interrupt priority level (ILVL2 to ILVL0) of
the interrupt used to exit wait mode
Set the interrupt priority level of the interrupts,
which are not used to exit wait mode, to 0
FLG register: set IPL
Bits RLVL2 to RLVL0 = the same level as IPL
Select the operating mode from the following:
-main clock mode
-low-speed mode
-on-chip oscillator mode
-on-chip oscillator low-power consumption mode
I flag = 1
Execute the WAIT instruction
Wait mode
(3) After exiting wait mode
RLVL register: bits RLVL2 to RLVL0 = 7
End
Figure 9.14 Procedure to Enter Wait Mode
Initial setting for the wait/stop mode
exit interrupt priority level
Interrupt disabled
(ILVL2 to ILVL0) > IPL* = (RLVL2 to RLVL0)*
Set the processor interrupt priority level (IPL)*
Set the exit interrupt priority level (RLVL2 to RLVL0)*
When the CM02 bit in the CM0 register is 1,
set bits MCD4 to MCD0 in the MCD register
for the CPU frequency to be 10 MHz or less.
Interrupt enabled
(note) Insert at least 4 NOP's after WAIT instruction.
Set the exit priority level as soon as exiting wait mode
Rev.1.00 Jul 15, 2007 Page 88 of 352
REJ09B0385-0100