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Rev. 1.00
46
October 26, 2018
Rev. 1.00
47
October 26, 2018
BS86DH12C
High Voltage Touch A/D Flash MCU with HVIO
BS86DH12C
High Voltage Touch A/D Flash MCU with HVIO
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 FAST 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
FAST
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
IDLE2
Off
1
0
000~110
On
On
Off
On
111
Off
SLEEP
Off
0
0
xxx
Off
Off
Off
On
(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. In the SLEEP mode, the f
LIRC
clock is on as the WDT function is always enabled.
FAST Mode
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 the high speed oscillator. This mode operates
allowing the microcontroller to operate normally with a clock source coming from the HIRC
oscillator. 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 determined by the FSS bit in the SCC register.
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. The f
SUB
clock provided to the
peripheral function will also be stopped, too. However the f
LIRC
clock continues to operate as the
WDT function is enabled.
IDLE0 Mode
The IDLE0 Mode is entered when an HALT instruction is executed and when the FHIDEN bit in the
SCC register is low and the FSIDEN bit in the SCC register is high. In the IDLE0 Mode the CPU
will be switched off but the low speed oscillator will be on to drive some peripheral functions.
IDLE1 Mode
The IDLE1 Mode is entered when an HALT instruction is executed and when the FHIDEN bit in the
SCC register is high and the FSIDEN bit in the SCC register is high. In the IDLE1 Mode the CPU
will be switched off but both the high and low speed oscillators will be on to provide a clock source
to keep some peripheral functions operational.