Overview Of 16-Bit Reload Timer - Fujitsu MB90480 Series Hardware Manual

CHAPTER 14 16-BIT RELOAD TIMER

14.1 Overview of 16-Bit Reload Timer

The 16-bit reload timer has the following functions:
• Clock mode can be selected from the internal clock mode and event count mode.
• When an underflow of 16-bit timer register (TMR) occurs, the count operation can be
selected either the one-shot mode that stops the operation or the reload mode that
continues its operation by reloading count setting value.
• When an underflow of 16-bit timer register (TMR) generated, the timer can be used
as the interval timer by generating an interrupt.
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Operation modes of the 16-bit reload timer
Operation modes of the 16-bit reload timer are shown below.
Internal clock mode
Event count mode
(External clock mode)
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Internal clock mode
One type of count clock can be selected among three types of internal clocks.
❍ Software trigger operation
Sets the TRG bits of the timer control status register (TMCSR) to "1" to start a counting
operation. Trigger input by the TRG bit can also be enabled when external trigger operation and
external gate input operation are performed.
❍ External trigger operation
Starts counting operation when the selected edge (rising, falling edges, or both) is input to the
TIN0 pin.
❍ External gate input operation
Continues counting operation while the selected signal ("L" or "H") is input to the TIN0 pin.
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Event count mode (external clock mode)
The function that starts countdown when the selected edge (rising, falling, or both) is input to the
TIN0 pin. This can also be used as an interval timer if an external clock with constant interval
time is used.
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Clock mode
Reload mode
One-shot mode
Reload mode
One-shot mode
Counting 16-bit reload timer operation
Software trigger operation
External trigger operation
External gate input operation
Software trigger operation