67
Figure 3.3 shows the timing of the setting of IRQnF.
ø
IRQn
input pin
IRQnF
Figure 3.3 Timing of Setting of IRQnF
The vector numbers for IRQ15 to IRQ0 interrupt exception handling are 31 to 16.
Detection of IRQ15 to IRQ0 interrupts does not depend on whether the relevant pin has been set
for input or output. When a pin is used as an external interrupt input pin, clear the corresponding
DDR bit to 0 and do not use the pin as an I/O pin for another function.
When interrupt request generation by a low level at the
IRQ
pin is selected for an IRQ15 to IRQ0
interrupt by means of an ISCR setting, when an interrupt is requested the relevant
IRQ
pin should
be held low until interrupt handling starts. The
IRQ
pin should then be returned to the high level,
and IRQnF (n = 0 to 15) cleared, in the interrupt handling routine. If the
IRQ
pin is returned to the
high level before interrupt handling is started, the associated interrupt may not be executed.
3.4.2
Internal Interrupts
There are 56 sources for internal interrupts from on-chip supporting modules.
1. For each on-chip supporting module there are flags that indicate the interrupt request status,
and enable bits that select enabling or disabling of these interrupts. If any one of these is set to
1, an interrupt request is issued to the interrupt controller.
2. The interrupt priority level can be set by means of IPR.
3. The DMAC and DTC can be activated by a TPU, SCI, or other interrupt request. When the
DMAC or DTC is activated by an interrupt, the interrupt control mode and CPU interrupt mask
bits have no effect.
Summary of Contents for H8S/2670
Page 5: ......
Page 9: ......
Page 199: ...182 ...
Page 361: ...344 ...
Page 393: ...376 ...
Page 647: ...630 ...