Rohm LAPIS SEMICONDUCTOR ML620Q503, User Manual

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ML620Q503/Q504 User's Manual
Chapter 4 Power Management
FEUL620Q504 4-15
Figure 4-5 Operation Waveforms in STOP Mode When CPU Operates with Low-Speed Clock
4.3.2.2 Oscillation Stop and Restart Timing of High-Speed Clock
When the STP bit of SBYCON is set to “1” with the stop code acceptor enabled while the high-speed clock is
operating, the mode changes to the STOP mode and the high-speed oscillation and low-speed oscillation stop.
When an external pin interrupt request that is interrupt-enabled (the interrupt enable flag is “1”) is issued, the
STP bit is set to “0”, and the high-speed oscillation and low-speed oscillation restart.
After generating interrupt request, low-speed built-in RC oscillation begins oscillating independently of the clock
mode. And, the clock is supplied as LSCLK after counts 29. And the counts 512, as OSCLK clock supply after
the high-speed built-in RC oscillation starts oscillation.
In the case of high-speed crystal/ceramic oscillation mode, oscillation is started after high-speed oscillation start
time (T
XTH
) from LSCLK supply. And, OSCLK changes from RC oscillation into crystal oscillation by the
automatic operation after counts 4096 by the crystal oscillation.
In the case of high-speed external clock mode, OSCLK changes from RC oscillation into external clock by the
automatic operation after counts 128 by the external clock from LSCLK supply.
For the high-speed oscillation start time (T
XTH
) and low-speed oscillation start time (T
XTL
), see the “Electrical
Characteristics” Section in Appendix C.
Figure 4-6 shows the operation waveforms in STOP mode when CPU operates with the high-speed clock.
Low-speed RC
oscillation
Oscillation
waveform
SYSCLK
SBYCON.STP bit
LSCLK
crystal RC
OSCLK
program operational mode STOP mode program operational mode
Interrupt request
29 counts Oscillation
waveform
T
XTL
Low-speed
crystal oscillation
8192 counts
crystal oscillation
RC oscillation
High-speed RC
oscillation
Oscillation waveform
512 counts
Oscillation waveform
T
XTH
High-speed
crystal oscillation
4096 counts
crystal