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Rev. 1.10
36
March 02, 2020
Rev. 1.10
37
March 02, 2020
BS83A02L/BS83B04L
Ultra-Low Power Touch Key Flash MCU
BS83A02L/BS83B04L
Ultra-Low Power Touch Key Flash MCU
High Speed
Oscillator
Prescaler
HIRC
f
H
f
H
/2
f
H
/4
f
H
/8
f
H
/16
f
H
/32
f
H
/64
f
SYS
Low Speed
Oscillator
LIRC
f
LIRC
/8
IDLE0
SLEEP
IDLE2
SLEEP
f
SUB
f
SUB
2MHz/64
4MHz/128
8MHz/256
f
32K
f
LIRC
CKS[2:0]
HIRCEN
: 2MHz/64 or 4MHz/128 for BS83B04L only.
System Clock Configurations
Internal High Speed RC Oscillator – HIRC
The internal RC oscillator is a fully integrated system oscillator requiring no external components.
For the BS83A02L, the internal RC oscillator has a fixed frequency of 8MHz. For the BS83B04L,
the internal RC oscillator has three fixed frequencies of 2MHz, 4MHz and 8MHz, which is selected
using a configuration option. The HIRC1~HIRC0 bits in the HIRCC register must also be setup to
match the selected configuration option frequency. Setting up these bits is necessary to ensure that
the HIRC frequency accuracy specified in the A.C. Characteristics is achieved. Device trimming
during the manufacturing process and the inclusion of internal frequency compensation circuits are
used to ensure that the influence of the power supply voltage, temperature and process variations on
the oscillation frequency are minimised.
Internal 2kHz Oscillator – LIRC
The Internal 2kHz System Oscillator is the low frequency oscillator. It is a fully integrated RC
oscillator with a typical frequency of 2kHz at full voltage range, requiring no external components
for its implementation. Device trimming during the manufacturing process and the inclusion of
internal frequency compensation circuits are used to ensure that the influence of the power supply
voltage, temperature and process variations on the oscillation frequency are minimised.