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Rev. 1.21
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HT66F488/HT66F489
A/D Flash MCU with EEPROM
HT66F488/HT66F489
A/D Flash MCU with EEPROM
Standard Type TM – STM
The Standard Type TM contains five operating modes, which are Compare Match Output, Timer/
Event Counter, Capture Input, Single Pulse Output and PWM Output modes. The Standard TM can
drive one external output pin.
Standard Type TM Block Diagram
Standard TM Operation
At its core is a 16-bit count-up counter which is driven by a user selectable internal clock source.
There are also two internal comparators with the names, Comparator A and Comparator P. These
comparators will compare the value in the counter with CCRP and CCRA registers. The CCRP is 8-bit
wide whose value is compared with the highest 8 bits in the counter while the CCRA is 16 bits and
therefore compares with all counter bits.
The only way of changing the value of the 16-bit counter using the application program, is to
clear the counter by changing the STON bit from low to high. The counter will also be cleared
automatically by a counter overflow or a compare match with one of its associated comparators.
When these conditions occur, a TM interrupt signal will also usually be generated. The Standard
Type TM can operate in a number of different operational modes, can be driven by different clock
sources including an input pin and can also control an output pin. All operating setup conditions are
selected using relevant internal registers.