Datasheet

Section 12 Timer W
Rev. 3.00 Sep. 14, 2006 Page 172 of 408
REJ09B0105-0300
12.4 Operation
The timer W has the following operating modes.
• Normal Operation
• PWM Operation
12.4.1 Normal Operation
TCNT performs free-running or periodic counting operations. After a reset, TCNT is set as a free-
running counter. When the CTS bit in TMRW is set to 1, TCNT starts incrementing the count.
When the count overflows from H'FFFF to H'0000, the OVF flag in TSRW is set to 1. If the OVIE
in TIERW is set to 1, an interrupt request is generated. Figure 12.2 shows free-running counting.
TCNT value
H'FFFF
H'0000
CTS bit
OVF
Time
Flag cleared
by software
Figure 12.2 Free-Running Counter Operation