Datasheet

Section 13 Timer W
Rev. 3.00 Mar. 15, 2006 Page 194 of 526
REJ09B0060-0300
13.4 Operation
The timer W has the following operation modes:
• Normal Operation
• PWM Operation
13.4.1 Normal Operation
TCNT performs free-running or periodic counting operations. After a reset, TCNT is set as a free-
running counter. When the CST 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 13.2 shows free-running counting.
TCNT value
H'FFFF
H'0000
CST bit
OVF
Time
Flag cleared
by software
Figure 13.2 Free-Running Counter Operation