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FUJITSU MB91460 SERIES FR60 User Manual

Page 252

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Chapter 16 Clock Supervisor

4.Operation Modes

Stop mode

If

RC-oscillator, main clock and sub-clock supervisors are enabled, they will be automatically disabled at

transition into stop mode. The corresponding enable bits in the clock supervisor control register remain
unchanged. So after wake-up from stop mode the RC-oscillator and the clock supervisors will be enabled again. If
the corresponding enable bits are set to ’0’, the RC-oscillator and the clock supervisors will stay disabled after
wake-up from stop mode.

The RC-oscillator is enabled immediately after wake-up from stop mode.

The main clock supervisor is enabled after the ’oscillation stabilisation wait time’ with the rising edge of the
signal OSC_STAB or in case the main clock is missing after wake-up from stop mode, after the ’main clock
timeout’ (TO_MCLK) from the timeout counter. The timeout counter is clocked with RC-oscillation clock.

The sub-clock supervisor is enabled after the ’sub-clock timeout’ (TO_SCLK) from the timeout counter which is
clocked with the RC-oscillation clock.

Figure 4-11 Timing Diagram: Waking up from stop mode

PONR

MCLK

SCLK

RC_CLK

OSC_STAB

MSVE

MSEN

SSVE

SSEN

MCLK_STBY

SCLK_STBY

TO_MCLK

TO_SCLK

EXT_RST

EXT_RST_OUT

MCLK_OUT

SCLK_OUT

MCLK_MISSING

SCLK_MISSING

SRST

RCE

Clock Mode

Main

Stop

Main

Sub