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1 sleep mode, Sleep mode – FUJITSU F2MCTM-16LX User Manual

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CHAPTER 8 LOW-POWER CONSUMPTION MODE

8.5.1

Sleep Mode

This mode causes the CPU operating clock to stop during operation in each clock
mode. The CPU stops, and peripheral function operates.

Switching to Sleep Mode

Writing 1 in the SLP bit and 0 in the STP bit of the low-power consumption mode control register

(LPMCR) triggers a switch to a sleep mode according to setting of the MCS and SCS bits in the clock

selection register (CKSCR). Table 8.5-2 shows the correspondence between MCS and SCS bits in the clock

selection register (CKSCR) and sleep mode.

Note:

When 1 is written to the SLP and STP bits of the low-power consumption mode control register

(LPMCR) at the same time, the STP bit setting overrides the SLP bit setting and the mode switches to

the stop mode. When 1 is written to the SLP bit and 0 is written to the TMD bit at the same time, the

TMD bit setting overrides the SLP bit setting and the mode switches to the timebase timer mode or

watch mode.

Data retention function

In a sleep mode, the contents of dedicated registers, such as accumulators, and the internal RAM are

retained.

Table 8.5-2 Setting of Clock Selection Register (CKSCR) and Sleep Mode

Clock selection register (CKSCR)

Sleep mode to be switched

MCS

SCS

1

1

Main sleep mode

0

1

PLL sleep mode

1

0

Sub-sleep mode

0

0