BAT32G1x9 user manual | Chapter 4 Clock generation circuit
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Rev.1.02
4.4.3
High-speed internal oscillator
The BAT32G179 has a built-in high-speed internal oscillator. Can choose the frequency from 64MHz, 48MHz,
32MHz, 24MHz, 16MHz, 12MHz, 8MHz, 6MHz, 4MHz, 3MHz, 2MHz and 1MHz via option byte ( 000C2H). Oscillation can
be controlled by bit0 (HIOSTOP) of the clock operating state control register (CSC).
After the reset is released, the high-speed internal oscillator automatically begins oscillating
.
4.4.4
Low-speed internal oscillator
The BAT32G179 has a low-speed internal oscillator.
The low-speed internal oscillator clock is used as a watchdog timer, a real-time clock, a clock for a 15-bit interval timer,
and a clock for timer A, as well as an external reference clock for the SysTick timer, but cannot be used as a CPU clock.
W hen the bit4(W DTON)of o pt ion b yte ( 000C0H) or bit4 (WUTMMCK0) of the subsystem clock provides
mode control register (OSMC) oscillates at a low speed internal oscillator when it is "1".
When the watchdog timer stops running and the WUTMMCK0 bit is not "0", the low-speed internal oscillator continues
to oscillate. However, if the watchdog timer is running and the WUTMMCK0 bit is "0", then the WDSTBYON bit is "0" and is
in sleep mode, deep sleep the low-speed internal oscillator stops oscillating in mode. When the watchdog timer is running,
the low-speed internal oscillator clock does not stop running even if the program is out of control.