Toshiba TXZ+ Series Reference Manual page 21

(2) fosc setup (Internal oscillation → External clock input)
As a f setup, the example of switching procedure to the external clock input (EHCLKIN) from an internal
osc
oscillation 1(IHOSC1) is shown below.
<< The state before switching >>
[CGOSCCR]<IHOSC1EN> = 1
[CGOSCCR]<OSCSEL> = 0
[CGOSCCR]<OSCF> = 0
Clock into to EHCLKIN
<< The example of switching procedure >>
[PYPDN]<bit[1:0]> = 00
1 [PYPUP]<bit[1:0]> = 00
[PYIE]<bit[0]> = 1
2 [CGOSCCR]<EOSCEN[1:0]> = 10
3 [CGOSCCR]<OSCSEL> = 1
4 [CGOSCCR]<OSCF> is read
5 [CGOSCCR]<IHOSC1EN> = 0
(3) fosc setup (External oscillation/External clock input → Internal oscillation)
As a f setup, the example of switching procedure to the internal high speed oscillation1 (IHOSC1) from an
osc
external high speed oscillation (EHOSC) Operation State or an external clock input (EHCLKIN) Operation State is
shown below.
<< The state before switching >>
[CGOSCCR]<EOSCEN[1:0]> = 01 or 10
[CGOSCCR]<OSCSEL> = 1
[CGOSCCR]<OSCF> = 1
<< The example of switching procedure >>
1 [CGWUPHCR]<WUCLK>=0
2 [CGWUPHCR]<WUPT[15:4]>=0x03C
3 [CGOSCCR]<IHOSC1EN> = 1
[CGWUPHCR]<WUON> = 1
4
5 Read [CGWUPHCR]<WUEF>
6 [CGOSCCR]<OSCSEL> = 0
7 [CGOSCCR]<OSCF> is read
8 [CGOSCCR]<EOSCEN[1:0]> = 00
An internal high speed oscillator1 oscillates.
The high speed oscillation selection for fosc is an inside (IHOSC1).
The high speed oscillation selection status for fosc is an inside
(IHOSC1).
Input in the proper voltage range.
Disable the pull-down resistor of X1 and X2 pins.
Disable the pull-up resistors of X1 and X2 pins.
Enable the input control of X1/EHCLKIN pin.
Selection of an external oscillation of operation is carried out to an
external clock input (EHCLKIN).
It is high speed oscillation selection for fosc to an external clock.
It waits until the high speed oscillation selection status for fosc
becomes outside (= 1).
An internal high speed oscillator1 is suspended.
Selection of an external oscillator of operation is an external high speed
oscillator (EHOSC) or external clock input.
The high speed oscillation selection for fosc is the exterior (EHOSC).
The high speed oscillation selection status for fosc is the exterior
(EHOSC).
Set the warming-up clock selection to internal high speed oscillator1
(IHOSC1).
Set the high speed oscillation warming-up timer setting value of 163.4
μs (=0x3C) or more.
An internal high speed oscillator1 is oscillated.
Start the high speed oscillation warming up timer.
Wait until an warming up timer status flag becomes ends(=1).
It is high speed oscillation selection for fosc to an internal clock
(IHOSC1).
It waits until the internal high speed oscillation selection status for fosc
becomes an inside (= 0).
Set the selection of an external oscillator operation to unused.
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TMPM4G Group(1)
Clock Control and Operation Mode
TXZ+ Family
2021-06-30
Rev. 1.1