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CHAPTER 20 16-BIT RELOAD TIMER
20.1 Overview
20.1
Overview
The 16-bit reload timer has two counter operating modes in each of the two
clock modes.
The 16-bit reload timer can be used as an interval timer by generating an
interrupt when an underflow occurs in the timer.
■ Operation Modes of 16-bit Reload Timer
Table 20.1-1 shows the operation modes of the 16-bit reload timer.
Table 20.1-1 Operation Modes of 16-bit Reload Timer
Internal clock mode
Event count mode
(external clock mode)
■ Internal Clock Mode
Internal clock mode is selected when any value other than "0b111" is set in the count clock
setting bits (CSL[2:0]) of the timer control status register upper (TMCSRHn).
In internal clock mode, the following three trigger operation modes are available.
● Software trigger operation
The count starts when the count enable bit (CNTE) in the timer control status register lower
(TMCSRLn) is set to "1" and the software trigger bit (TRG) is set to "1".
● External trigger input operation
When the count enable bit (CNTE) in the timer control status register lower (TMCSRLn) is set
to "1", the count will start if a valid edge (rising, falling, or both selectable) specified by the
operating mode select bits (MOD[2:0]) is input to the TIn pin.
● External gate input operation
When the count enable bit (CNTE) in the timer control status register lower (TMCSRLn) is set
to "1", the count will start if a valid trigger input level ("L" or "H" selectable) specified by the
operating mode select bits (MOD[2:0]) is input to the TIn pin.
■ Event Count Mode (External Clock Mode)
When the count clock setting bits (CSL[2:0]) in the timer control status register upper
(TMCSRHn) are set to "0b111", the count will start if a valid edge of trigger input (rising,
falling, or both) specified by the operating mode select bits (MOD[2:0]) is input to the TIn pin.
When an external clock is input in regular cycles, the reload timer can also be used as an
interval timer.
354
Clock mode
Counter operating mode
FUJITSU SEMICONDUCTOR LIMITED
Reload mode
External trigger input operation
One-shot mode
Reload mode
One-shot mode
MB95630H Series
Trigger operation mode
Software trigger operation
External gate input operation
Software trigger operation
MN702-00009-1v0-E
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