Holtek BS83B24C Manual page 139

BS83B24C/BS83C40C
Touch Flash MCU
• TKC0 Register
Bit 7
Name TKRAMC TKRCOV
R/W R/W
POR 0
Bit 7 TKRAMC: Touch key data memory access control
0: Accessed by MCU
1: Accessed by touch key module
This bit determines that the touch key data memory is used by the MCU or the touch
key module. However, the touch key module will have the priority to access the touch
key data memory when the touch key module operates in the auto scan mode, i.e., the
TKST bit state is changed from 0 to 1 when the TKMOD bit is set low. After the touch
key auto scan operation is completed, i.e., the TKBUSY bit state is changed from 1 to 0,
the touch key data memory access will be controlled by the TKRAMC bit. Therefore,
it is recommended to set the TKRAMC bit to 1 when the touch key module operates
in the auto scan mode. Otherwise, the contents of the touch key data memory may be
modified as this data memory space is configured by the touch key module followed
by the MCU access.
Bit 6 TKRCOV: Touch key time slot counter overflow flag
0: No overflow occurs
1: Overflow occurs
This bit can be accessed by application program. Note that this bit can not be set by
application program but must be cleared to 0 by application program.
In the auto scan mode, if module 0 or all module time slot counter, selected by the
TSCS bit, overflows but touch key scan is not completed, the TKRCOV bit will not
be set, all module 16-bit C/F counter, 16-bit counter and 5-bit time slot counter will
be automatically cleared but the 8-bit time slot timer counter will be reloaded from
8-bit time slot timer counter preload register. When touch key scan is completed, the
TKRCOV bit and the Touch Key Interrupt request flag, TKMF, will be set and all
module key oscillators and reference oscillators will automatically stop. All module
16-bit C/F counter, 16-bit counter, 5-bit time slot counter and 8-bit time slot timer
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 Interrupt request
flag, TKMF, will be set , all module key oscillators and reference oscillators will
automatically stop. All module 16-bit C/F counter, 16-bit counter, 5-bit time slot
counter and 8-bit time slot timer 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 high by the touch key module 16-bit C/F counter overflow and must be
cleared to 0 by application programs.
Rev. 1.00
6 5 4
TKST TKC�OV
R/W R/W R/W
0 0 0
139
3 2 1
TK16OV — TKMOD
R/W — R/W
0 — 0
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0
TKBUSY
R
0