NEC mPD789026 Subseries, User Manual

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User's Manual U11919EJ3V0UM00
105
CHAPTER 7 8-BIT TIMER/EVENT COUNTER
7.1 8-Bit Timer/Event Counter Functions
8-bit timer/event counter 00 (TM00) has the following functions:
•
Interval timer
•
External event counter
•
Square wave output
(1) 8-bit interval timer
When the 8-bit timer/event counter is used as an interval timer, it generates an interrupt at any time
intervals set in advance.
Table 7-1. Interval Time of 8-Bit Timer/Event Counter 00
Minimum Interval Time Maximum Interval Time Resolution
1/f
X
(200 ns) 2
8
/f
X
(51.2
µ
s) 1/f
X
(200 ns)
2
5
/f
X
(6.4
µ
s) 2
13
/f
X
(1.64 ms) 2
5
/f
X
(6.4
µ
s)
Remarks 1. f
X
: System clock oscillation frequency
2. The parenthesized values apply to operation at f
X
= 5.0 MHz.
(2) External event counter
The number of pulses of an externally input signal can be measured.
(3) Square wave output
A square wave of arbitrary frequency can be output.
Table 7-2. Square Wave Output Range of 8-Bit Timer/Event Counter 00
Minimum Pulse Width Maximum Pulse Width Resolution
1/f
X
(200 ns) 2
8
/f
X
(51.2
µ
s) 1/f
X
(200 ns)
2
5
/f
X
(6.4
µ
s) 2
13
/f
X
(1.64 ms) 2
5
/f
X
(6.4
µ
s)
Remarks 1. f
X
: System clock oscillation frequency
2. The parenthesized values apply to operation at f
X
= 5.0 MHz.