M16C65 Datasheet, PDF (178/829 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
9.3.4 Stop Mode
In stop mode, all oscillator circuits, the CPU clock, and peripheral function clocks are turned off.
Therefore, the CPU and the peripheral functions using these clocks stop operating. The least amount of
power is consumed in this mode. If the voltage applied to pins VCC1 and VCC2 is VRAM or greater, the
contents of internal RAM are retained. When applying 2.7 V or less to pins VCC1 and VCC2, make sure
VCC1 ≥ VCC2 ≥ VRAM.
However, the peripheral functions activated by external signals keep operating.
9.3.4.1 Entering Stop Mode
The MCU enters stop mode by setting the CM10 bit in the CM1 register to 1 (all clocks turned off). At
the same time, the CM06 bit in the CM0 register is set to 1 (divide-by-8 mode), and the CM15 bit in
the CM1 register is set to 1 (main clock oscillator circuit drive capability high).
Before entering stop mode, set the CM20 bit to 0 (oscillation stop/re-oscillation detection function
disabled).
Also, when the CM11 bit is 1 (PLL clock used as the CPU clock source), set the CM11 bit to 0 (main
clock used as the CPU clock source), and then the PLC07 bit to 0 (PLL turned off) before entering
stop mode.
9.3.4.2 Pin Status in Stop Mode
Table 9.8 lists Pin Status in Stop Mode.
Table 9.8 Pin Status in Stop Mode
Pin
A0 to A19, D0 to D15,
CS0 to CS3, BHE
RD, WR, WRL, WRH
HLDA, BCLK
ALE
I/O ports
CLKOUT fC selected
f1, f8, f32 selected
Memory Expansion Mode
Microprocessor Mode
Retains status just prior to stop
mode
High
High
Undefined
Retains status just prior to stop
mode
Cannot be used as CLKOUT pin
XOUT
XCIN, XCOUT
High
High-impedance
Single-Chip Mode
Cannot be used as bus control pin
Retains status just prior to stop
mode
High
Retains status just prior to stop
mode
REJ09B0484-0030 Rev.0.30 Sep 09, 2008
Page 143 of 791