Group N Interrupt Control Registers - Panasonic MN103S User Manual

5.2.5

Group n Interrupt Control Registers

G2ICR to G30ICR registers are designed to control the level interrupts for groups 2 to 30, respectively.
The interrupt priority level is controlled by the GnLV2 to GnLV0 flags. When the interrupt level set in the GnLV2
to GnLV0 flags is smaller than the IM2 to IM0 flags in the PSW, interrupts of the corresponding the interrupt
group can be generated. Interrupts in the same interrupt group (max.4 interrupts) are the interrupt level specified
by GnLV2 to GnLV0 flags. If interrupt requests are issued by multiple interrupt groups at the same time, the inter-
rupt group with the highest interrupt priority level is accepted. In addition, if the interrupt priority levels of multi-
ple interrupt groups are set to the same level, the interrupt from the interrupt group with the highest interrupt
priority level (the interrupt group with the smallest group number) is accepted.
An interrupt is enabled by the GnIE flag. The bits of the GnIE flag correspond to the interrupt factors (max.4 fac-
tors) of the interrupt group. When the GnIE flag is "1", the interrupt corresponding to this flag is enabled. When
the GnIR flag is in "1" state and the GnIE flag is set to "1", an interrupt is generated.
An interrupt request is controlled by the GnIR flag. The bits of the GnIR flag correspond to interrupts respec-
tively. The GnIR flag is cleared by software in the interrupt processing program after the interrupt is accepted.
When clearing the GnIR flag to "0", set the GnIR flag to "0" and the corresponding GnID flag to "1".
An interrupt detection is controlled by the GnID flag. The logical product of the GnIE and InIR flags is stored. If
the interrupt enabled by the GnIE flag is generated, the GnID flag corresponding to the interrupt changes to "1". It
is used for specifying the interrupt factor of the group in the interrupt processing program. The interrupt request is
released by writing the specified value on the GnIR and GnID flags and clearing the GnIR flag.
Table:5.2.6 Changes of the GnIR flag and GnID flag
Write data
GnIR
0
0
1
1
All values except the IR and ID remain unchanged wring.
GnID GnIR
0 No change
1 0
0 No change
1 1
Result of write
GnID
No change
0
No change
IE value
Chapter 5
Interrupt Controller
Control Registers V - 13