BS85B12-3 HOLTEK [Holtek Semiconductor Inc], BS85B12-3 Datasheet - Page 90

• Manufacturer Part Number: BS85B12-3
• Description: Touch Key Flash Type 8-Bit MCU with LCD/LED Driver
• Manufacturer: HOLTEK [Holtek Semiconductor Inc]

Enhanced Type TM - ETM
Rev. 1.00
BS85B12-3
BS85C20-3
Enhanced TM Operation
CTM
The Enhanced Type TM contains five operating modes, which are Compare Match Output,
Timer/Event Counter, Capture Input, Single Pulse Output and PWM Output modes. The Enhanced
TM can also be controlled with an external input pin and can drive three or four external output pins.
At its core is a 10-bit count-up/count-down counter which is driven by a user selectable internal or
external clock source. There are three internal comparators with the names, Comparator A,
Comparator B and Comparator P. These comparators will compare the value in the counter with the
CCRA, CCRB and CCRP registers. The CCRP comparator is 3-bits wide whose value is compared
with the highest 3-bits in the counter while CCRA and CCRB are 10-bits wide and therefore compared
with all counter bits.
The only way of changing the value of the 10-bit counter using the application program, is to clear the
counter by changing the TnON 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 Enhanced 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 output pins. All operating setup conditions are selected using relevant internal
registers.
10-bit ETM
10-bit ETM
Name
Touch Key Flash MCU with LCD/LED Driver
Enhanced Type TM Block Diagram
TM No.
1
1
84
TM Input Pin
TCK1
TCK1
BS85B12-3/BS85C20-3
TP1A, TP1B_0, TP1B_1, TP1B_2
TP1A, TP1B_0, TP1B_1, TP1B_2
TM Output Pin
February 1, 2011