UPD784938 Datasheet, PDF (272/733 Pages) NEC – 16-Bit Single-Chip Microcontrollers

CHAPTER 10 TIMER/EVENT COUNTER 1
(2) Pulse width measurement
Detects the pulse width of the signal input to the external interrupt request input pin INTP0.
Table 10-2. Timer/Event Counter 1 Pulse Width Measurement Range
Measurable Pulse Width^Note
Resolution
4/fXX to 2¹⁶ × 4/fXX
(0.32 µs)
(20.8 ms)
4/fXX
(0.32 µs)
8/fXX to 2¹⁶ × 8/fXX
(0.64 µs)
(41.7 ms)
8/fXX
(0.64 µs)
16/fXX to 2¹⁶ × 16/fXX
(1.27 µs)
(83.4 ms)
16/fXX
(1.27 µs)
32/fXX to 2¹⁶ × 32/fXX
(2.54 µs)
(167 ms)
32/fXX
(2.54 µs)
64/fXX to 2¹⁶ × 64/fXX
(5.09 µs)
(333 ms)
64/fXX
(5.09 µs)
128/fXX to 2¹⁶ × 128/fXX
(10.17 µs) (667 ms)
128/fXX
(10.17 µs)
256/fXX to 2¹⁶ × 256/fXX
(20.35 µs)
(1.33 s)
256/fXX
(20.35 µs)
512/fXX to 2¹⁶ × 512/fXX
(40.70 µs)
(2.67 s)
512/fXX
(40.70 µs)
1,024/fXX to 2¹⁶ × 1,024/fXX
(81.40 µs)
(5.33 s)
1,024/fXX
(81.40 µs)
( ): When fXX = 12.58 MHz
Note
The minimum pulse width that can be measured changes depending on the sampling clock selected by the sampling
clock select register (SCS0). The minimum pulse width that can be measured is the value in the table below or above,
whichever is greater.
Sampling Clock
fCLK
fCLK = fXX
fCLK = fXX/2
fCLK = fXX/4
fCLK = fXX/8
fXX/32
fXX/64
fXX/128
at fXX = 12.58 MHz operation
Minimum Pulse Width
3/fCLK = 3/fXX (0.24 µs)
3/fCLK = 6/fXX (0.48 µs)
3/fCLK = 12/fXX (0.95 µs)
3/fCLK = 24/fXX (1.19 µs)
96/fXX (7.63 µs)
192/fXX (15.26 µs)
384/fXX (30.52 µs)
272
Preliminary User’s Manual U13987EJ1V0UM00