![](http://datasheet.mmic.net.cn/370000/UPD75236GJ_datasheet_16740772/UPD75236GJ_133.png)
133
μ
PD75236
5.2
INTERRUPT CONTROL CIRCUIT HARDWARE DEVICES
(1)
Interrupt request flag, interrupt enable flag
There are ten interrupt request flags (IRQXXX) corresponding to interrupt sources (interrupt :8, test :2)
as shown below.
INT0 interrupt request flag (IRQ0)
INT1 interrupt request flag (IRQ1)
INT2 interrupt request flag (IRQ2)
INT4 interrupt request flag (IRQ4)
BT interrupt request flag (IRQBT)
Serial interface interrupt request flag (IRQCSI0)
Timer/event counter interrupt request flag (IRQT0)
Timer/pulse generator interrupt request flag (IRQTPG)
Key scan interrupt request flag (IRQKS)
Watch timer interrupt request flag (IRQW)
Interrupt request flag is set to “1” at generation of an interrupt request and is automatically cleared
(“0”) upon execution of interrupt service. IRQBT and IRQ4 carry out clear operation differently because
they share the vector address. (See
5.5
VECTOR ADDRESS SHARING INTERRUPT SERVICE
.)
There are ten interrupt enable flags (IEXXX) corresponding to interrupt request flags as shown below.
INT0 interrupt enable flag (IE0)
INT1 interrupt enable flag (IE1)
INT2 interrupt enable flag (IE2)
INT4 interrupt enable flag (IE4)
BT interrupt enable flag (IEBT)
Serial interface interrupt enable flag (IECSI0)
Timer/event counter interrupt enable flag (IET0)
Timer/pulse generator interrupt enable flag (IETPG)
Key scan interrupt enable flag (IEKS)
Watch timer interrupt enable flag (IEW)
When the contents of interrupt enable flag is “1”, interrupt is enabled and when it is “0”, interrupt is
disabled.
When the interrupt request flag is set and the interrupt enable flag has enabled interrupt, the vectored
interrupt request (VRQn) is generated.
This signal is also used to release the standby mode.
Both the interrupt request flag and interrupt enable flag are operated by the bit manipulation instruc-
tion and 4-bit memory manipulation instruction. They can be operated directly by the bit manipulation
instruction irrespective of MBE setting. The interrupt enable flag is operated by the EI IE
×××
and DI IE
×××
instruction. The SKTCLR instruction is normally used to test the interrupt request flag.
When the interrupt request flag is set by an instruction even if an interrupt has not been generated, the
vectored interrupt is executed in the same way as when an interrupt had been generated.
RESET input clears the interrupt request flag and the interrupt enable flag (“0”) and disables all inter-
rupts.
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