hd64338023s Renesas Electronics Corporation., hd64338023s Datasheet - Page 321

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

The term of validity of “Interrupt factor generation signal”
Method 1 is recommended to operate for time efficiency.
All above attentions are also applied in 16-bit mode and 8-bit mode.
Method 1
1. Prohibit interrupt in interrupt handling routine (set IENFH, IENFL to 0).
2. After program process returned normal handling, clear interrupt request flags (IRRTFH,
3. After read timer control status register F (TCSRF), clear timer overflow flags (OVFH,
4. Operate interrupt permission (set IENFH, IENFL to 1).
Method 2
1. Set interrupt handling routine time to more than time that calculated with (1) formula.
2. Clear interrupt request flags (IRRTFH, IRRTFL) at the end of interrupt handling routine.
3. After read timer control status register F (TCSRF), clear timer overflow flags (OVFH,
IRRTFL) after more than that calculated with (1) formula.
OVFL) and compare match flags (CMFH, CMFL).
OVFL) and compare match flags (CMFH, CMFL).
= 1 cycle of φw + waiting time for completion of executing instruction
+ interrupt time synchronized with φ = 1/φw + ST • (1/φ) + (2/φ) (second).....(1)
ST: Executing number of execution states
Rev. 7.00 Mar 10, 2005 page 279 of 652
REJ09B0042-0700
Section 9 Timers