16-Bit Timer/Event Counter Functions; Bit Timer/Event Counter Interval Times - NEC PD78052 User Manual

8.2 16-Bit Timer/Event Counter Functions

The 16-bit timer/event counter (TM0) has the following functions.
• Interval timer
• PWM output
• Pulse width measurement
• External event counter
• Square-wave output
• One-shot pulse output
PWM output and pulse width measurement can be used at the same time.
(1) Interval timer
TM0 generates interrupt requests at the preset time interval.
Minimum Interval Time
MCS = 1 MCS = 0
2 TI00 input cycle
— 2
(400 ns)
2
2 1/f 2
X
(400 ns) (800 ns)
2 3
2 1/f 2
X
(800 ns) (1.6 s)
3 4
2 1/f 2
X
(1.6 s) (3.2 s)
2 watch timer output cycle
Remarks 1. f : Main system clock oscillation frequency
X
2. MCS: Oscillation mode selection register (OSMS) bit 0
3. Values in parentheses when operated at f
(2) PWM output
TM0 can generate 14-bit resolution PWM output.
(3) Pulse width measurement
TM0 can measure the pulse width of an externally input signal.
(4) External event counter
TM0 can measure the number of pulses of an externally input signal.
CHAPTER 8 16-BIT TIMER/EVENT COUNTER
Table 8-2. 16-Bit Timer/Event Counter Interval Times
Maximum Interval Time
MCS = 1
16
2 TI00 input cycle
1/f —
X
16
1/f 2 1/f
X X
(13.1 ms)
17
1/f 2 1/f
X X
(26.2 ms)
18
1/f 2 1/f
X X
(52.4 ms)
16
2 watch timer output cycle
MCS = 0 MCS = 1
TI00 input edge cycle
16
2 1/f —
X
(13.1 ms)
17
2 1/f 1/f
X
(26.2 ms) (200 ns)
18
2 1/f 2 1/f
X
(52.4 ms) (400 ns)
19 2
2 1/f 2 1/f
X
(104.9 ms) (800 ns)
Watch timer output edge cycle
= 5.0 MHz
X
Resolution
MCS = 0
1/f
X
(200 ns)
2 1/f
X X
(400 ns)
2
2 1/f
X X
(800 ns)
3
2 1/f
X X
(1.6 s)
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