Holtek BS66F340C Manual page 202

keys and reference oscillators will automatically stop. All touch key module 16-bit C/F
counter, touch key function 16-bit counter, 5-bit time slot unit period counter and 8-bit
time slot counter will be automatically switched off.
In the manual scan mode, if module 0 or all module time slot counter, selected by TSCS
bit, overflows, the TKRCOV bit and the Touch Key Module Interrupt request flag,
TKMF, will be set and all module keys and reference oscillators will automatically stop.
All touch key module 16-bit C/F counter, touch key function 16-bit counter, 5-bit time
slot unit period counter and 8-bit time slot counter will be automatically switched off.
Bit 5 TKST: Touch key detection Start control
0: Stopped or no operation
0→1: Start detection
In all modules, the touch key module 16-bit C/F counter, touch key function 16-bit
counter and 5-bit time slot unit period counter will automatically be cleared when this
bit is cleared to zero. However, the 8-bit programmable time slot counter will not be
cleared. When this bit is changed from low to high, the touch key module 16-bit C/F
counter, touch key function 16-bit counter, 5-bit time slot unit period counter and 8-bit
time slot counter will be switched on together with the key and reference oscillators to
drive the corresponding counters.
Bit 4 TKCFOV: Touch key module 16-bit C/F counter overflow flag
0: No overflow occurs
1: Overflow occurs
This bit is set by touch key module 16-bit C/F counter overflow and must be cleared to
0 by application program.
Bit 3 TK16OV: Touch key function 16-bit counter overflow flag
0: No overflow occurs
1: Overflow occurs
This bit is set by touch key function 16-bit counter overflow and must be cleared to 0
by application program.
Bit 2 Unimplemented, read as "0"
TKMOD: Touch key scan mode select
Bit 1
0: Auto scan mode
1: Manual mode
In the manual scan mode the reference oscillator capacitor value should be properly
configured before the scan operation begins and the touch key module 16-bit C/F
counter value should be read by application program after the scan operation finishes.
In the auto scan mode the data movement which is described above is implemented by
hardware. The individual reference oscillator capacitor value and 16-bit C/F counter
content for all scanned keys will be read from and written into a dedicated Touch Key
Data Memory area. In the auto scan mode the keys to be scanned can be arranged in
a specific sequence which is determined by the MnSK3[1:0]~MnSK0[1:0] bits in the
TKMnC2 register. The scan operation will not be stopped until all arranged keys are
scanned.
Bit 0 TKBUSY: Touch key scan operation busy flag
0: Not busy – No scan operation is executed or scan operation is completed
1: Busy – Scan operation is executing
This bit indicates whether the touch key scan operation is executing or not. It is set to
1 when the TKST bit is set high to start the scan operation.
In the manual scan mode this bit is cleared to 0 automatically when module 0 or all
module time slot counter, selected by TSCS bit, overflows. In the auto scan mode this
bit is cleared to 0 automatically when the touch key scan operation is completed.
Rev. 1.11
BS66F340C/BS66F350C/BS66F360C
Touch A/D Flash MCU
202 November 09, 2023