Rev. 1.00
46
September 11, 2018
Rev. 1.00
47
September 11, 2018
HT45F4050
A/D NFC Flash MCU
HT45F4050
A/D NFC Flash MCU
HXTEN
LXTEN
HIRCEN
HXT
Prescaler
f
H
LXT
High Speed
Oscillators
Low Speed
Oscillators
f
H
/2
f
H
/16
f
H
/64
f
H
/8
f
H
/4
f
H
/32
CKS2~CKS0
f
SYS
f
SUB
f
SUB
FSS
LIRC
f
LIRC
f
LIRC
HIRC
f
H
LVR
WDT
f
LIRC
f
SYS
/4
Time Base 0
f
SUB
f
SYS
Prescaler 0
TB0 [2:0]
TB1 [2:0]
f
SYS
/4
f
SUB
f
SYS
Prescaler 1
FHS
CLKSEL0[1:0]
CLKSEL1[1:0]
Time Base 1
f
PSC0
f
PSC1
IDLE0
SLEEP
IDLE2
SLEEP
Device Clock Configurations
Note: When the system clock source f
SYS
is switched to f
SUB
from f
H
, the high speed oscillation
can be stopped to conserve the power or continue to oscillate to provide the clock source,
f
H
~f
H
/64, for peripheral circuit to use, which is determined by configuring the corresponding
high speed oscillator enable control bit.
System Operation Modes
There are six different modes of operation for the microcontroller, each one with its own special
characteristics and which can be chosen according to the specific performance and power requirements
of the application. There are two modes allowing normal operation of the microcontroller, the
NORMAL Mode and SLOW Mode. The remaining four modes, the SLEEP, IDLE0, IDLE1 and
IDLE2 Mode are used when the microcontroller CPU is switched off to conserve power.
Operation
Mode
CPU
Related Register
f
SYS
f
H
f
SUB
f
LIRC
FHIDEN
FSIDEN
CKS[2:0]
NORMAL
On
x
x
000~110
f
H
~f
H
/64
On
On
On
Slow
On
x
x
111
f
SUB
On/Off
(1)
On
On
IDLE0
Off
0
1
000~110
Off
Off
On
On
111
On
IDLE1
Off
1
1
xxx
On
On
On
On
IDLE 2
Off
1
0
000~110
On
On
Off
On
111
Off
SLEEP
Off
0
0
xxx
Off
Off
Off
On/Off
(2)
"x ": Don’t care
Note: 1.
The f
H
clock will be switched on or off by configuring the corresponding oscillator enable
bit in the SLOW mode.
2. The f
LIRC
clock can be switched on or off which is controlled by the WDT function being
enabled or disabled in the SLEEP mode.