Rohm LAPIS SEMICONDUCTOR ML620Q503, User Manual

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ML620Q503/Q504 User's Manual
Chapter 6 Clock Generation Circuit
FEUL620Q504 6–8
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LOSCON (bit 11)
The LOSCON bit also permits the low-speed crystal oscillator circuit to oscillate when the low-speed
built-in RC oscillation mode is selected. When LOSCON is turned to "1", the low-speed crystal
oscillator circuit is enabled to oscillate at the same time even though the built-in RC oscillation mode is
selected by the XTM1 or XTM0 bit.
Note that the low-speed crystal oscillation clock at this time is supplied only to the timer block. Clocks
selected by the XTM1 and XTM0 bits are supplied to peripherals other than the timer block. If the
low-speed crystal oscillation is selected as the clock for timer block, set the LOSCON bit to "1".
LOSCON Description
0 Prohibit low-speed crystal oscillation when the low-speed built-in RC oscillation
mode is selected (initial value)
1 Permit low-speed crystal oscillation when the low-speed built-in RC oscillation mode
is selected
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LOSST (bit 14)
LOSST is the flag used to indicate the oscillation state of the low-speed crystal oscillator circuit.
LOSST Description
0 The low-speed crystal oscillation has stopped, or the low-speed crystal oscillation
stabilization time is being counted (initial value)
1 The low-speed crystal oscillation is in the stable state
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HOSST (bit 15)
HOSST is the flag used to indicate the oscillation state of the high-speed crystal/ceramic oscillator
circuit.
HOSST Description
0 The high-speed crystal/ceramic oscillation has stopped, or the stabilization time is
being counted (initial value)
1 The high-speed crystal/ceramic oscillation is in the stable state
[Note]
•When switching the high-speed clock mode using the OSCM1 and OSCM0 bits, please first stop the
high-speed oscillation(set the ENOSC bit of FCON1 register to “0”) and then set the system clock to the
low-speed clock (set the SYSCLK bits of the FCON1 register to "0").
• In the high-speed external clock input mode, input a clock that does not exceed 16MHz.