Stop Mode - Renesas M16C/6NK Hardware Manual

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M16C/6N Group (M16C/6NK, M16C/6NM)

8.4.3 Stop Mode

In stop mode, all oscillator circuits are turned off, so are the CPU clock and the peripheral function clocks.
Therefore, the CPU and the peripheral functions clocked by these clocks stop operating. The least
amount of power is consumed in this mode. If the voltage applied to VCC is VRAM or more, the internal
RAM is retained.
However, the peripheral functions clocked by external signals keep operating.
Table 8.6 lists the interrupts to stop mode and use conditions.
Table 8.6 Interrupts to Stop Mode and Use Conditions
Interrupt
_______
NMI Interrupt
Key Input Interrupt
______
INT Interrupt
Timer A Interrupt
Timer B interrupt
Serial Interface Interrupt
CAN0/1 Wake-up Interrupt
8.4.3.1 Entering Stop Mode
The microcomputer is placed into 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 in the CM2 register to "0" (oscillation stop, re-oscillation
detection function disabled).
Also, if the CM11 bit in the CM1 register is "1" (PLL clock for the CPU clock source), set the CM11 bit to
"0" (main clock for the CPU clock source) and the PLC07 bit in the PLC0 register to "0" (PLL turned off)
before entering stop mode.
8.4.3.2 Pin Status in Stop Mode
Table 8.7 lists the pin status in stop mode.
Table 8.7 Pin Status in Stop Mode
Pin
A0 to A19, D0 to D15,
_______ _______ ________
(2)
CS0 to CS3, BHE
______ _______ _________ _________
RD, WR, WRL, WRH
___________
(2)
HLDA, BCLK
(2)
ALE
I/O ports
CLKOUT When fC selected
When f8, f32
selected
NOTES:
1. Not available memory expansion and microprocessor modes in T/V-ver..
2. Not available the bus control pins in T/V-ver..
Rev.2.00 Nov 28, 2005
REJ09B0124-0200
Can be used
Can be used
Can be used
Can be used
(when counting external pulses in event counter mode)
Can be used (when external clock is selected)
Can be used (when CAN sleep mode is selected)
Memory Expansion Mode
Microprocessor Mode
Retains status before stop mode
(2)
"H"
"H"
indeterminate
Retains status before stop mode
Does not become a CLKOUT pin
page 73 of 378
Condition
Single-chip Mode
(1)
Does not become a bus control pin
Retains status before stop mode
"H"
Retains status before stop mode
8. Clock Generating Circuit