Rev. 1.40
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Rev. 1.40
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BS67F340/BS67F350/BS67F360/BS67F370
Enhanced Touch A/D Flash MCU with LCD Driver
BS67F340/BS67F350/BS67F360/BS67F370
Enhanced Touch A/D Flash MCU with LCD Driver
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
Register Setting
f
SYS
f
H
f
SUB
f
LIRC
FHIDEN FSIDEN CKS2~CKS0
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�
Off
1
0
000~110
On
On
Off
On
111
Off
SLEEP
Off
0
0
xxx
Off
Off
Off
On
(�)
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 will be switched on since the WDT function is always enabled.
NORMAL Mode
As the name suggests this is one of the main operating modes where the microcontroller has all of
its functions operational and where the system clock is provided by one of the high speed oscillators.
This mode operates allowing the microcontroller to operate normally with a clock source will come
from one of the high speed oscillators, either the HXT or HIRC oscillators. The high speed oscillator
will however first be divided by a ratio ranging from 1 to 64, the actual ratio being selected by
the CKS2~CKS0 bits in the SCC register.Although a high speed oscillator is used, running the
microcontroller at a divided clock ratio reduces the operating current.
SLOW Mode
This is also a mode where the microcontroller operates normally although now with a slower speed
clock source. The clock source used will be from f
SUB
. The f
SUB
clock is derived from either the
LIRC or LXT oscillator.
SLEEP Mode
The SLEEP Mode is entered when an HALT instruction is executed and when the FHIDEN and
FSIDEN bit are low. In the SLEEP mode the CPU will be stopped
.
However the f
LIRC
clock still
continues to operate since the WDT function is always enabled.