TMP86FS28DFG datasheet(117/272 Pages) TOSHIBA

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Page 105

TMP86FS28DFG

8.2.3.5 Pulse Width Measurement Mode

In the pulse width measurement mode, the up-counter starts counting by the input pulse triggering of the

TC11 pin, and counts up at the edge of the internal clock. Either the rising or falling edge of the internal

clock is selected as the trigger edge in TC11CR<TC11S>. Either the single- or double-edge capture is

selected as the trigger edge in TC11CR<MCAP11>.

• When TC11CR<MCAP11> is set to “1” (single-edge capture)

Either high- or low-level input pulse width can be measured. To measure the high-level input

pulse width, set the rising edge to TC11CR<TC11S>. To measure the low-level input pulse

width, set the falling edge to TC11CR<TC11S>.

When detecting the edge opposite to the trigger edge used to start counting after the timer

starts, the up-counter captures the up-counter value into TC11DRB and generates an INTTC11

interrupt request. The up-counter is cleared at this time, and then restarts counting when detect-

ing the trigger edge used to start counting.

• When TC11CR<MCAP11> is set to “0” (double-edge capture)

The cycle starting with either the high- or low-going input pulse can be measured. To mea-

sure the cycle starting with the high-going pulse, set the rising edge to TC11CR<TC11S>. To

measure the cycle starting with the low-going pulse, set the falling edge to TC11CR<TC11S>.

When detecting the edge opposite to the trigger edge used to start counting after the timer

starts, the up-counter captures the up-counter value into TC11DRB and generates an INTTC11

interrupt request. The up-counter continues counting up, and captures the up-counter value into

TC11DRB and generates an INTTC11 interrupt request when detecting the trigger edge used to

start counting. The up-counter is cleared at this time, and then continues counting.

Note 1: The captured value must be read from TC11DRB until the next trigger edge is detected. If not read,

the captured value becomes a don’t care. It is recommended to use a 16-bit access instruction to read

the captured value from TC11DRB.

Note 2: For the single-edge capture, the counter after capturing the value stops at “1” until detecting the next

edge. Therefore, the second captured value is “1” larger than the captured value immediately after

counting starts.

Note 3: The first captured value after the timer starts may be read incorrectively, therefore, ignore the first

captured value.

TMP86FS28DFG データシート(PDF) 117 Page - Toshiba Semiconductor