HD64336901G Renesas Technology, HD64336901G Datasheet - Page 192

• Manufacturer Part Number: HD64336901G
• Description: (HD64xxx Series) 16-BIT MICROCONTROLLER
• Manufacturer: Renesas Technology

12.4
The timer W has the following operating modes.
12.4.1
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.
Periodic counting operation can be performed when GRA is set as an output compare register and
bit CCLR in TCRW is set to 1. When the count matches GRA, TCNT is cleared to H'0000, the
IMFA flag in TSRW is set to 1. If the corresponding IMIEA bit in TIERW is set to 1, an interrupt
request is generated. TCNT continues counting from H'0000. Figure 12.3 shows periodic
counting.
Rev. 1.00, 11/03, page 164 of 376
Normal Operation
PWM Operation
Operation
Normal Operation
H'FFFF
H'0000
CTS bit
OVF
TCNT value
Figure 12.2 Free-Running Counter Operation
Flag cleared
by software
Time