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
Each touch key module contains four touch key inputs which are shared logical I/O pins, and
the desired function is selected using register bits. Each touch key has its own independent sense
oscillator. There are therefore four sense oscillators within each touch key module.
During this reference clock fixed interval, the number of clock cycles generated by the sense
oscillator is measured, and it is this value that is used to determine if a touch action has been made
or not. At the end of the fixed reference clock time interval a Touch Key interrupt signal will be
generated in the manual scan mode.
Using the TSCS bit in the TKC1 register can select the module 0 time slot counter as the time
slot counter for all modules. All modules use the same started signal, TKST, in the TKC0 register.
The touch key module 16-bit C/F counter, 16-bit counter, 5-bit time slot unit period counter in
all modules will be automatically cleared when the TKST bit is cleared to zero, but the 8-Bit
programmable time slot counter will not be cleared. The overflow time is setup by user. When the
TKST bit changes from low to high, the 16-bit C/F counter, 16-bit counter, 5-bit time slot unit period
counter and 8-bit time slot timer counter will be automatically switched on.
The key oscillator and reference oscillator in all modules will be automatically stopped and the 16-
bit C/F counter, 16-bit counter, 5-bit time slot unit period counter and 8-bit time slot timer counter
will be automatically switched off when the time slot counter overflows. The clock source for
the time slot counter is sourced from the reference oscillator or f
SYS
/4 which is selected using the
MnTSS bit in the TKMnC1 register. The reference oscillator and key oscillator will be enabled by
setting the MnROEN bit and MnKOEN bits in the TKMnC1 register.
When the time slot counter in all the touch key modules or in the touch key module 0 overflows,
an actual touch key interrupt will take place. The touch keys mentioned here are the keys which are
enabled.
Each touch key module consists of four touch keys, KEY1 ~ KEY4 are contained in module 0,
KEY5 ~ KEY8 are contained in module 1, KEY9 ~ KEY12 are contained in module 2, etc. Each
touch key module has an identical structure.
Auto Scan Mode
There are two scan modes contained for the touch key function. The auto scan mode can minisize
the load of the application programs and improve the touch key scan operation performance. The
auto scan mode and manual scan mode are selected using the TKMOD bit in the TKC0 register.
When the TKMOD bit is set low, the auto scan mode is selcted to scan the keys in each module in a
specific sequence determined by the MnSK3[1:0]~MnSK0[1:0] in the TKMnC2 register.