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(3) External Interrupt 0 and 1 Request Flags (IF0: $000, 2 , IF1: $001, 0*): IF0 and IF1 are
flags that reflect whether an interrupt request is outstanding on the corresponding
INT
0 and INT1
external interrupt pin. When the specified input edge is detected on an external interrupt pin, the
corresponding external interrupt request flag is set to 1.
Only falling edges are detected on the
INT
0 and INT1 pins.
The IF0 and IF1 flags can be read and written only by the bit manipulation instructions. However,
note that only a 0 may be written.
IF0 and IF1 are never cleared automatically, even when an interrupt is received. They must be
cleared to 0 by the software.
These flags are cleared to 0 on reset and in stop mode.
IF0, IF1*
Description
0
Indicates that no interrupt has been requested on the corresponding
INT
0 or INT1.
(initial value)
1
Indicates that an interrupt has been requested on the corresponding
INT
0 or INT1.
Note: * The external interrupt 1 request flag (IF1) applies to the HD404318, HD404358,
HD404358R, HD404339, and HD404369 Series. Since there is no
INT
1 pin in HD404344R
and HD404394 Series products, the IF1 flag cannot be used in those products.
(4) External Interrupt 0 and 1 Masks (IM0: $000, 3, IM1: $001, 1*): IM0 and IM1 are bits
that mask the corresponding IF0 and IF1 flags. The CPU will accept an external interrupt when
IF0 or IF1 is set to 1 only if the corresponding IM0 or IM1 is cleared to 0 and IE is 1.
The CPU will not receive an interrupt request from IF0 or IF1 if the corresponding IM0 or IM1 is
set to 1. That is, the interrupt will be deferred.
IM0 and IM1 can be read and written only by the bit manipulation instructions.
These masks are set to 1 on reset and in stop mode.
IM0, IM1*
Description
0
IF0 or IF1 is enabled.
1
IF0 or IF1 is masked. The interrupt will be deferred even if either IF0 or IF1 is set
to 1.
(initial value)
Note: * The external interrupt 1 mask (IM1) applies to the HD404318, HD404358, HD404358R,
HD404339, and HD404369 Series. Since there is no
INT
1 pin in HD404344R and
HD404394 Series products, the IM1 mask cannot be used in those products.