H838532H datasheet(263/508 Pages) RENESAS

263 / 508 page

Section 9 Timers

Rev. 1.00 May 30, 2008 Page 243 of 484

REJ09B0436-0100

The term of validity of “Interrupt factor generation signal”

= 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

Method 1 is recommended to operate for time efficiency.

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,

IRRTFL) after more than that calculated with (1) formula.

3. After read timer control status register F (TCSRF), clear timer overflow flags (OVFH,

OVFL) and compare match flags (CMFH, CMFL).

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,

OVFL) and compare match flags (CMFH, CMFL).

All above attentions are also applied in 16-bit mode and 8-bit mode.

H838532H 데이터시트(PDF) 263 Page - Renesas Technology Corp