HT69F30A Datasheet, PDF (93/202 Pages) Holtek Semiconductor Inc – TinyPowerTM I/O Flash 8-Bit MCU with LCD & EEPROM

HT69F30A/HT69F40A/HT69F50A
TinyPower^TM I/O Flash 8-Bit MCU with LCD & EEPROM
Timer Modules – TM
One of the most fundamental functions in any microcontroller device is the ability to control and
measure time. To implement time related functions each device includes several Timer Modules,
abbreviated to the name TM. The TMs are multi-purpose timing units and serve to provide
operations such as Timer/Counter, Input Capture, Compare Match Output and Single Pulse Output
as well as being the functional unit for the generation of PWM signals. Each of the TMs has either
two or three individual interrupts. The addition of input and output pins for each TM ensures that
users are provided with timing units with a wide and flexible range of features.
The common features of the different TM types are described here with more detailed information
provided in the individual Compact, Standard and Enhanced TM sections.
Introduction
The devices contain from two to three TMs depending upon which device is selected with each
TM having a reference name of TM0, TM1, and TM2. Each individual TM can be categorised as
a certain type, namely Compact Type TM, Standard Type TM or Enhanced Type TM. Although
similar in nature, the different TM types vary in their feature complexity. The common features
to all of the Compact, Standard and Enhanced TMs will be described in this section, the detailed
operation regarding each of the TM types will be described in separate sections. The main features
and differences between the three types of TMs are summarised in the accompanying table.
TM Function
Timer/Counter
I/P Capture
Compare Match Output
PWM Channels
Single Pulse Output
PWM Alignment
PWM Adjustment Period & Duty
CTM
√
—
√
1
—
Edge
Duty or Period
STM
√
√
√
1
1
Edge
Duty or Period
ETM
√
√
√
2
2
Edge & Centre
Duty or Period
TM Function Summary
Each device in the series contains a specific number of either Compact Type, Standard Type and
Enhanced Type TM unit which are shown in the table together with their individual reference name,
TM0~TM2.
Device
HT69F30A
HT69F40A
HT69F50A
TM0
TM1
10-bit CTM
10-bit STM
10-bit CTM
10-bit ETM
10-bit CTM
10-bit ETM
TM Name/Type Reference
TM2
—
10-bit STM
16-bit STM
TM Operation
The three different types of TM offer a diverse range of functions, from simple timing operations
to PWM signal generation. The key to understanding how the TM operates is to see it in terms of
a free running counter whose value is then compared with the value of pre-programmed internal
comparators. When the free running counter has the same value as the pre-programmed comparator,
known as a compare match situation, a TM interrupt signal will be generated which can clear the
counter and perhaps also change the condition of the TM output pin. The internal TM counter is
driven by a user selectable clock source, which can be an internal clock or an external pin.
Rev. 1.00
93
March 19, 2013