TMPM330 - Keil

Under development
8.6 Applications using the Capture Function
TMPM330 (rev 0.4)8-30
TMPM330
The capture function can be used to develop many applications, including those described below:
One-shot pulse output triggered by an external pulse
Frequency measurement
Pulse width measurement
Time difference measurement
One-shot pulse output triggered by an external pulse
One-shot pulse output triggered by an external pulse is carried out as follows:
The 16-bit up-counter is made to count up by putting it in a free-running state using the prescaler
output clock. An external pulse is input through the TB5IN0 pin. A trigger is generated at the rising of
the external pulse by using the capture function and the value of the up-counter is taken into the
capture registers (TB5CP0).
The NVIC must be programmed so that an interrupt INTCAP50 is generated at the rising of an
external trigger pulse. This interrupt is used to set the timer registers (TB5RG0) to the sum of the
TB5CP0 value (c) and the delay time (d), (c + d), and set the timer registers (TB5RG1) to the sum of
the TB5RG0 values and the pulse width (p) of one-shot pulse, (c + d + p).
TB5RG1 change must be completed before the next match.
In addition, the timer flip-flop control registers (TB5FFCR) must be set to “11.”
This enables triggering the timer flip-flop (TB5FF0) to reverse when UC5 matches TB5RG0 and
TB5RG1. This trigger is disabled by the INTTB5 interrupt after a one-shot pulse is output.
Symbols (c), (d) and (p) used in the text correspond to symbols c, d and p in Fig. 8-5 One-shot Pulse
Output (With Delay).”
Count clock
(Internal clock)
TB5IN0 pin input
(External trigger pulse)
Match with TB5RG0
Match with TB5RG1
Timer output TB5OUTpin
Put the counter in a free-running state.
c
Enable reverse
Disable reverse when
data is taken into CAP5.
Delay time
(d)
c + d
Enable
reverse
Pulse width
(p)
c + d + p
Taking data into the capture register (CAP5)
INTCAP50 generation
INTTB5 generation
Fig. 8-5 One-shot Pulse Output (With Delay)
INTTB5 generation
16-bit Timer/
Event Counters (TMRBs)