Rev. 1.10
60
November 04, 2019
Rev. 1.10
61
November 04, 2019
HT45F5Q-3
Battery Charger Flash MCU
HT45F5Q-3
Battery Charger Flash MCU
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 two
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 and Standard TM sections.
Introduction
The device contains two TMs and each individual TM can be categorised as a certain type, namely
Compact Type TM or Standard Type TM. Although similar in nature, the different TM types vary
in their feature complexity. The common features to all of the Compact and Standard 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 two types of TMs are summarised
in the accompanying table.
Function
CTM
STM
Timer/Counter
√
√
Input Capture
—
√
Compare Match Output
√
√
PWM Output
√
√
Single Pulse Output
—
√
PWM Alignment
Edge
Edge
PWM Adjustment Period & Duty
Duty or Period
Duty or Period
TM Function Summary
TM Operation
The 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.
TM Clock Source
The clock source which drives the main counter in each TM can originate from various sources. The
selection of the required clock source is implemented using the xTCK2~xTCK0 bits in the xTM
control registers, where “x” stands for C or S type TM. The clock source can be a ratio of the system
clock f
SYS
or the internal high clock f
H
, the f
SUB
clock source or the external xTCK pin. The xTCK
pin clock source is used to allow an external signal to drive the TM as an external clock source or
for event counting.
