CHAPTER 6 16-BIT TIMER/EVENT COUNTER 00
Preliminary User’s Manual U16898EJ1V0UD
102
Figure 6-24. Timing of Pulse Width Measurement Operation by Free-Running Counter
and Two Capture Registers (with Rising Edge Specified)
t
0000H
0000H
FFFFH
0001H
D0
D0
D2
D1
D3
D2
D3
D1
D0 + 1
D2 + 1
D1 + 1
INTTM010
OVF00
CR000 capture value
Count clock
TM00 count value
TI000 pin input
CR010 capture value
(D1
−
D0)
×
t
(D3
−
D2)
×
t
(10000H
−
D1 + D2)
×
t
Note
Note OVF00 must be cleared by software.
(4) Pulse width measurement by means of restart
When input of a valid edge to the TI000 pin is detected, the count value of 16-bit timer/counter 00 (TM00) is
taken into 16-bit timer capture/compare register 010 (CR010), and then the pulse width of the signal input to
the TI000 pin is measured by clearing TM00 and restarting the count.
The edge specification can be selected from two types, rising or falling edges, by bits 4 and 5 (ES000 and
ES010) of prescaler mode register 00 (PRM00)
Sampling is performed at the interval selected by prescaler mode register 00 (PRM00) and a capture operation
is only performed when a valid level of the TI000 pin is detected twice, thus eliminating noise with a short
pulse width.
Caution If the valid edge of TI000 is specified to be both the rising and falling edges, 16-bit timer
capture/compare register 000 (CR000) cannot perform the capture operation.
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