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CHAPTER 11 16-BIT RELOAD TIMER
11.1 Overview of the 16-Bit Reload Timer
The MB90560 and 565 series have two channels of 16-bit reload timer. The following
two clock modes and the following two counter operation modes can be selected.
Clock modes
Internal clock mode: The timer counts down in synchronization with the internal
clock.
Event count mode: The timer counts down in synchronization with the external
input pulse.
Counter operation modes
Reload mode: The timer repeats counting by reloading the count setting value.
One-shot mode: The timer stops counting when an underflow occurs.
s 16-bit reload timer operating modes
s Internal Clock Mode
The 16-bit reload timer is in internal clock mode if the count clock setting bits (CSL1, CSL0) of
the timer control status register (TMCSR) are set to "00B", "01B", or "10B".
For internal clock mode, select one of the following three operations:
r Software trigger operation
Counting starts when the software trigger bit (TRG) is set to "1" while the count enable bit
(CNTE) of the TMCSR register is set to "1".
r External trigger operation
Counting starts when a valid edge (rising, falling, or both edges) of trigger input specified in the
operation mode setting bits (MOD2, MOD1, and MOD0) is input to the TIN pins while the CNTE
bit of the TMCSR register is set to "1".
r External gate input operation
Counting continues while a valid level of gate input ("L" or "H") specified in the operation mode
setting bits (MOD2, MOD1, and MOD0) is input to the TIN pins while the CNTE bit of the
TMCSR register is set to "1".
Table 11.1-1 16-Bit Reload Timer Operating Modes
Clock mode
Counter operation
Operation of 16-bit reload timer
Internal clock mode
Reload mode
Software trigger operation
External trigger operation
External gate input operation
One-shot mode
Event count mode
(external clock mode)
Reload mode
Software trigger operation
One-shot mode