M16C62P_06 Datasheet, PDF (111/421 Pages) Renesas Technology Corp – 16-BIT SINGLE-CHIP MICROCOMPUTER M16C FAMILY / M16C/60 SERIES

M16C/62P Group (M16C/62P, M16C/62PT)
10. Clock Generation Circuit
10.4.2 Wait Mode
In wait mode, the CPU clock is turned off, so are the CPU (because operated by the CPU clock) and the
watchdog timer. However, if the PM22 bit in the PM2 register is “1” (on-chip oscillator clock for the watchdog
timer count source), the watchdog timer remains active. Because the main clock, sub clock and on-chip
oscillator clock all are on, the peripheral functions using these clocks keep operating.
10.4.2.1 Peripheral Function Clock Stop Function
If the CM02 bit in the CM0 register is “1” (peripheral function clocks turned off during wait mode), the f1, f2,
f8, f32, f1SIO, f8SIO, f32SIO and fAD clocks are turned off when in wait mode, with the power consumption
reduced that much. However, fC32 remains on.
10.4.2.2 Entering Wait Mode
The microcomputer is placed into wait mode by executing the WAIT instruction.
When the CM11 bit = 1 (CPU clock source is the PLL clock), be sure to clear the CM11 bit in the CM1 register
to “0” (CPU clock source is the main clock) before going to wait mode. The power consumption of the chip can
be reduced by clearing the PLC07 bit in the PLC0 register to “0” (PLL stops).
10.4.2.3 Pin Status During Wait Mode
Table 10.4 lists Pin Status During Wait Mode.
Table 10.4 Pin Status During Wait Mode
Pin
Memory Expansion Mode
Microprocessor Mode
Single-Chip Mode
A0 to A19, D0 to D15, CS0 to CS3, ^{Retains status before wait mode Does not become a bus control}
BHE
pin
RD, WR, WRL, WRH
“H”
HLDA, BCLK
“H”
ALE
“L”
I/O ports
Retains status before wait mode Retains status before wait mode
CLKOUT When fC selected
Does not become a CLKOUT pin Does not stop
When f8, f32 selected
Does not stop when the CM02 bit
is “0”.
When the CM02 bit is “1”, the
status immediately prior to
entering wait mode is
maintained.
Rev.2.41 Jan 10, 2006 Page 96 of 390
REJ09B0185-0241