hd64338023s Renesas Electronics Corporation., hd64338023s Datasheet - Page 322

• Manufacturer Part Number: hd64338023s
• Description: Renesas 8-bit Single-chip Microcomputer Super Low Power Series
• Manufacturer: Renesas Electronics Corporation.

Section 9 Timers
Timer Counter (TCF) Read/Write
When φw/4 is selected as the internal clock in active (high-speed, medium-speed) mode, write on
TCF is impossible. And, when read TCF, as the system clock and internal clock are mutually
asynchronous, TCF synchronizes with synchronization circuit. This results in a maximum TCF
read value error of ±1.
When read/write TCF in active (high-speed, medium-speed) mode is needed, please select internal
clock except for φw/4 before read/write.
In subactive mode, even φw/4 is selected as the internal clock, normal read/write TCF is possible.
Rev. 7.00 Mar 10, 2005 page 280 of 652
REJ09B0042-0700
Figure 9.7 Clear Interrupt Request Flag when Interrupt Factor Generation Signal is Valid
Program process
Interrupt factor
generation signal
(Internal signal,
nega-active)
Overflow signal,
Compare match signal
(Internal signal,
nega-active)
Interrupt request flag
(IRRTFH, IRRTFL)
φ
W
Interrupt
Interrupt request
flag clear
(1)
(2)
Interrupt
Interrupt request
flag clear
Normal