PD17012_15 Datasheet, PDF (133/320 Pages) Renesas Technology Corp – 4-BIT SINGLE-CHIP MICROCONTROLLERS WITH DIGITAL TUNING SYSTEM HARDWARE

µPD17012, 17P012
Figure 12-12. Error of Basic Timer 1 (2/2)
(b) When basic timer 1 interrupt pulse is changed
Internal H
pulse A L
Internal H
pulse B L
Basic timer 1 ^H
interrupt pulse L
1
IRQBTM1 flag ₀
1
IPBTM1 flag
0
EI
INTE FF
DI
EI ^{<1> Basic timer 1 interrupt} EI
pulse changed
EI ^{<3> Basic timer 1 interrupt} EI
pulse changed
Interrupt acknowledged
<2> Interrupt acknowledged Interrupt acknowledged
Even if the basic timer 1 interrupt pulse is changed to B at point <1> in the above figure, the interrupt is
acknowledged at the next point <2> because the basic timer 1 interrupt pulse does not fall.
If the basic timer 1 interrupt pulse is changed to A at <3>, the interrupt is immediately acknowledged
because the basic timer 1 interrupt pulse falls.
(c) When IRQBTM1 flag is manipulated
Basic timer 1 ^H
interrupt pulse L
1
IRQBTM1 flag ₀
1
IPBTM1 flag
0
EI
INTE FF
DI
EI
EI
EI
Interrupt acknowledged
<1> SET1 IRQBTM1
interrupt
acknowledged
<2> CLR1 IRQBTM1
interrupt not
acknowledged
Interrupt acknowledged
The interrupt is immediately acknowledged if the IRQBTM1 flag is set to 1 at <1>.
If clearing the IRQBTM1 flag to 0 overlaps with the falling of the basic timer 1 interrupt pulse at <2>, the
interrupt is not acknowledged.
Data Sheet U10101EJ4V0DS
131