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User’s Manual U12790EJ2V0UD
CHAPTER 7 8-BIT TIMER/EVENT COUNTERS 50, 51
7.1 Functions of 8-Bit Timer/Event Counters 50, 51
8-bit timer/event counters 50 and 51 have the following two modes.
Mode in which an 8-bit timer/event counter is used alone (single mode)
Mode in which the two timer/event counters are connected in cascade (cascade connection mode with a
resolution of 16 bits)
These two modes are explained below.
(1) Mode in which an 8-bit timer/event counter is used alone (single mode)
The timer/event counter operates as an 8-bit timer/event counter.
In this mode, the following functions can be used.
<1> Interval timer
Interrupt requests are generated at the preset interval.
Number of counts: 1 to 256
<2> External event counter
The number of pulses with high/low level widths in a signal input externally can be measured.
<3> Square-wave output
A square wave with an arbitrary frequency can be output.
Cycle: (1
× 2 to 256 × 2) × Count clock cycle
<4> PWM output
A pulse with an arbitrary duty ratio can be output.
Cycle:
Count clock
× 256
Duty ratio: Set value of compare register/256
(2) Mode in which the two timer/event counters are connected in cascade (cascade connection mode with
a resolution of 16 bits)
By combining the two 8-bit timer/event counters, they can operate as a 16-bit timer/event counter.
In this mode, the following functions can be used.
Interval timer with 16-bit resolution
External event counter with 16-bit resolution
Square-wave output with 16-bit resolution
Figures 7-1 and 7-2 show the block diagrams of 8-bit timer/event counters 50 and 51.