BAT32G1x9 user manual | Chapter 4 Clock generation circuit
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Rev.1.02
4.3.6
Oscillation settling time selection register (OSTS).
This is the register that selects the oscillation settling time of the X1 clock.
If the X1 clock oscillates, the time to automatically wait for the OSTS register to be set just after the X1
oscillation circuit runs (MSTOP=0).
If the CPU clock is switched from a high-speed internal oscillator clock or a sub-system clock to an X1 clock,
or if the CPU clock is a high-speed internal oscillator clock and the deep sleep mode is transferred to deep sleep
mode in the state of X1 clock oscillation, deep sleep mode is exited, The oscillation settling time counter must be
used to confirm whether the oscillation settling time has passed through the state register (OSTC) of the oscillation
settling time counter.
The OSTC register can be used to confirm the time set in advance by the OSTS register.
Set the OSTS register via the 8-bit memory operation instruction. After generating a reset signal, the
value of this register becomes "07H".
Figure 4-8 Oscillation Settling Time Selection Register (OSTS) Format
Address: 40020403H
after reset:
07H R/W
SYMBOL
7
6
5
4
3
2
1
0
OSTS
OSTS2
OSTS1
OSTS0
The selection of oscillation stabilization time
f
X
=10MHz
f
X
=20MHz
0
0
0
2
8
/f
X
25.6us
12.8us
0
0
1
2
9
/f
X
51.2us
25.6us
0
1
0
2
10
/f
X
102us
51.2us
0
1
1
2
11
/f
X
204us
102us
1
0
0
2
13
/f
X
819us
409us
1
0
1
2
15
/f
X
3.27ms
1.63ms
1
1
0
2
17
/f
X
13.1ms
6.55ms
1
1
1
2
18
/f
X
26.2ms
13.1ms
Note 1
To change
the setting of the OSTS register, you must change it before placing the MSTOP position of CLOCK
Operating State Control Register (CSC) to "0".
2. The oscillation settling time counter is only counted within
the oscillation settling time set by the OSTS register.
In the following cases,
the setting value of the oscillation settling time of the OSTS register must be greater than
the count value confirmed by
the
OSTC
register after the start of oscillation.
• When the
CPU
clock is a high-speed internal oscillator clock or a subsystem clock and you want to start
oscillation of the
X1
clock
• When the
CPU
clock is a high-speed internal oscillator clock and
the deep sleep mode is exited after the X1
clock oscillates to deep sleep mode (so it must be noted that the OSTC register after deactivating deep sleep
mode
only sets
OSTS.) The state within the oscillation settling time set by the register).
3. The oscillation settling time of the X1 clock does not include the time before the clock begins to oscillate (Figure
a
below
).
Deep sleep mode is exited
X1 pin
Voltage waveform
a
Note f
X
:
X1
clock oscillation frequency
0
0
0
0
0
OSTS2
OSTS1
OSTS0