The Setting Method Of A System Clock; Fosc Setup (Internal Oscillation >>> External Oscillation); Table 1.7 Operating Frequency Examples Of High Speed And Middle Speed System Clocks - Toshiba TXZ+ TMPM4KLFYAUG Reference Manual

Table 1.7 Operating frequency examples of High speed and Middle speed system clocks

Note: The maximum frequency of Middle speed system clock is 80 MHz.

1.2.6.1. The setting method of a system clock

(1) fosc setup (Internal oscillation >>> External oscillation)
As a fosc setup, the example of switching procedure to the external high speed oscillator (EHOSC) from an
internal high speed oscillator1 (IHOSC1) is shown below.
<< The state before switching >>
[CGOSCCR]<IHOSC1EN> =1
[CGOSCCR]<OSCSEL> =0
[CGOSCCR]<OSCF> =0
An oscillator is connected to X1 / X2 pin.
<< The example of switching procedure >>
[PHPDN]<bit[1:0]> =00
1
[PHIE]<bit[1:0]> =00
2 [CGOSCCR]<EOSCEN[1:0]> =01
[CGWUPHCR]<WUCLK> =1
3 [CGWUPHCR]<WUPT[15:4]> =
arbitrary value
4 [CGWUPHCR]<WUON> =1
5 [CGWUPHCR]<WUEF> is read.
6 [CGOSCCR]<OSCSEL> =1
7 [CGOSCCR]<OSCF> is read
8 [CGOSCCR]<IHOSC1EN> =0
Middle speed system clock
High speed
fsysm (MHz)
system clock
fsysh (MHz)
1/1
160 -
80 80
An internal high speed oscillator1 oscillates.
The high speed oscillation selection for fosc is an internal high speed
oscillator1 (IHOSC1).
The high speed oscillation selection status for fosc is an internal high
speed oscillator1 (IHOSC1).
Do not connect any devices except a resonator.
Disable the pull-down resistors of X1 and X2 pins.
Disable input control of X1 and X2 pins.
It is an external high speed oscillator (EHOSC) about selection of an
external oscillation of operation.
It is the external high speed oscillator (EHOSC) about high speed
oscillation warming-up clock selection.
A warming-up timer setting value is set to oscillator stable time.
High speed oscillation warming-up is started.
It waits until it becomes the termination of high speed oscillation
warming-up (= 0).
It is high speed oscillation selection for fosc to the external high speed
oscillator (EHOSC).
It waits until the high speed oscillation selection status for fosc becomes
external high speed oscillator (=1).
An internal high speed oscillator1 is suspended.
19 / 68
Clock Control and Operation Mode
1/2 1/4
80 40
40 20
TXZ+ Family
TMPM4K Group(2)
2023-12-25
Rev. 3.0