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Section 5 Clock Pulse Generator
Page 128 of 2108 R01UH0134EJ0400 Rev. 4.00
Sep 24, 2014
SH7262 Group, SH7264 Group
5.7 Oscillation Stabilizing Time
5.7.1 Oscillation Stabilizing Time of the On-chip Crystal Oscillator
In the case of using a crystal resonator, please wait longer than the oscillation stabilizing time at
the following cases, to keep the oscillation stabilizing time of the on-chip crystal oscillator (In the
case of inputting an external clock input, it is not necessary).
Power on
Releasing the software standby mode or deep standby mode by RES pin
Changing from halting oscillation to running oscillation by power-on reset or register setting
(AUDIO_X1, RTC_X1)
Changing the gain of the on-chip crystal oscillator by RES pin (EXTAL)
5.7.2 Oscillation Stabilizing Time of the PLL circuit
The clock from EXTAL in the clock mode 0 and 2 or USB_X1 in the clock mode 1 and 3 is
supplied to the PLL circuit. So, regardless of whether using a crystal resonator or inputting an
external clock from EXTAL (clock mode 0 and 2) or USB_X1 (clock mode 1 and 3), please wait
longer than the oscillation stabilizing time at the following cases, to keep the oscillation stabilizing
time of the PLL circuit.
Power on (in the case of using the crystal resonator)/start inputting external clock (in the case
of inputting the external clock)
Releasing the software standby mode or deep standby mode by RES pin
[Remarks]
The oscillation stabilizing time is kept by the counter running in the LSI at the following cases.
Releasing the software standby mode or deep standby mode by the other than RES pin
Changing the gain of the on-chip crystal oscillator by the register setting (EXTAL)