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
Touch Key Operation
When a finger touches or is in proximity to a touch pad, the capacitance of the pad will increase.
By using this capacitance variation to change slightly the frequency of the internal sense oscillator,
touch actions can be sensed by measuring these frequency changes. Using an internal programmable
divider the reference clock is used to generate a fixed time period. By counting a number of
generated clock cycles from the sense oscillator during this fixed time period touch key actions can
be determined.
TKST
MnKOEN
MnROEN
KEY OSC CLK
Refe�en�e OSC CLK
f
CFTMCK
Ena�le
f
CFTMCK
(MnDFEN=0)
f
CFTMCK
(MnDFEN=0)
TKBUSY
TKRCOV
Hardware set to
“
0
”
Set Tou�h Key inte��upt �equest flag
Touch Key Manual Scan Mode Timing Diagram