M16C30P_07 Datasheet, PDF (70/317 Pages) Renesas Technology Corp – 16-BIT SINGLE-CHIP MICROCOMPUTER M16C FAMILY / M16C/30 SERIES

M16C/30P Group
9. Clock Generating Circuit
9.4.2.4 Exiting Wait Mode
The microcomputer is moved out of wait mode by a hardware reset, NMI interrupt or peripheral function
interrupt.
If the microcomputer is to be moved out of exit wait mode by a hardware reset or NMI interrupt, set the
peripheral function interrupt priority ILVL2 to ILVL0 bits to “000b” (interrupts disabled) before executing the
WAIT instruction.
The peripheral function interrupts are affected by the CM02 bit. If CM02 bit is “0” (peripheral function clocks
not turned off during wait mode), peripheral function interrupts can be used to exit wait mode. If CM02 bit is
“1” (peripheral function clocks turned off during wait mode), the peripheral functions using the peripheral
function clocks stop operating, so that only the peripheral functions clocked by external signals can be used to
exit wait mode.
Table 9.4 Interrupts to Exit Wait Mode and Use Conditions
Interrupt
CM02=0
CM02=1
NMI Interrupt
Can be used
Can be used
Serial Interface
Interrupt
Can be used when operating with
internal or external clock
Can be used when operating with
external clock
Key Input Interrupt Can be used
Can be used
A/D Conversion
Interrupt
Can be used in one-shot mode
−(Do not use)
Timer A Interrupt
Timer B Interrupt
Can be used in all modes
Can be used in event counter mode or
when the count source is fC32
INT Interrupt
Can be used
Can be used
Table 9.4 lists the Interrupts to Exit Wait Mode and Use Conditions.
If the microcomputer is to be moved out of wait mode by a peripheral function interrupt, set up the following
before executing the WAIT instruction.
(1) Set the ILVL2 to ILVL0 bits in the interrupt control register, for peripheral function interrupts used to
exit wait mode.
The ILVL2 to ILVL0 bits in all other interrupt control registers, for peripheral function interrupts not
used to exit wait mode, are set to “000b” (interrupt disable).
(2) Set the I flag to “1”.
(3) Start operating the peripheral functions used to exit wait mode.
When the peripheral function interrupt is used, an interrupt routine is performed as soon as an interrupt
request is acknowledged and the CPU clock is supplied again.
When the microcomputer exits wait mode by the peripheral function interrupt, the CPU clock is the same clock
as the CPU clock executing the WAIT instruction.
Rev.1.22 Mar 29, 2007 Page 54 of 291
REJ09B0179-0122