HYUNDAI MicroElectronics
16. INTERRUPTS
GMS81C2012/GMS81C2020
The GMS81C20xx interrupt circuits consist of Interrupt
enable register (IENH, IENL), Interrupt request flags of
IRQH, IRQL, Priority circuit, and Master enable flag (“I”
flag of PSW). Nine interrupt sources are provided. The
configuration of interrupt circuit is shown in Figure 16-2.
register (IENH, IENL), and the interrupt request flags (in
IRQH and IRQL) except Power-on reset and software
BRK interrupt. Below table shows the Interrupt priority.
Reset/Interrupt
Symbol
Priority
The External Interrupts INT0 and INT1 each can be transi-
tion-activated (1-to-0 or 0-to-1 transition) by selection
IEDS.
The flags that actually generate these interrupts are bit
INT0F and INT1F in register IRQH. When an external in-
terrupt is generated, the flag that generated it is cleared by
the hardware when the service routine is vectored to only
if the interrupt was transition-activated.
Hardware Reset
External Interrupt 0
External Interrupt 1
Timer/Counter 0
Timer/Counter 1
-
RESET
INT0
INT1
TIMER0
-
1
2
3
4
-
-
-
-
TIMER1
-
-
-
-
-
-
-
ADC Interrupt
Watchdog Timer
Basic Interval Timer
Serial Communication
ADC
WDT
BIT
SCI
5
6
7
8
The Timer 0 ~ Timer 1 Interrupts are generated by TxIF
which is set by a match in their respective timer/counter
register. The Basic Interval Timer Interrupt is generated by
BITIF which is set by an overflow in the timer register.
The AD converter Interrupt is generated by ADIF which is
set by finishing the analog to digital conversion.
The Watchdog timer Interrupt is generated by WDTIF
which set by a match in Watchdog timer register.
The Basic Interval Timer Interrupt is generated by BITIF
which are set by a overflow in the timer counter register.
Vector addresses are shown in Figure 8-6 on page 28. In-
terrupt enable registers are shown in Figure 16-3. These
registers are composed of interrupt enable flags of each in-
terrupt source and these flags determines whether an inter-
rupt will be accepted or not. When enable flag is “0”, a
corresponding interrupt source is prohibited. Note that
PSW contains also a master enable bit, I-flag, which dis-
ables all interrupts at once.
The interrupts are controlled by the interrupt master enable
flag I-flag (bit 2 of PSW on page 26), the interrupt enable
-
-
-
-
-
-
R/W R/W
R/W R/W
T0IF T1IF
-
ADDRESS: 0E4H
INITIAL VALUE: 0000 ----B
-
INT0IF INT1IF
IRQH
LSB
MSB
Timer/Counter 1 interrupt request flag
Timer/Counter 0 interrupt request flag
External interrupt 1 request flag
External interrupt 0 request flag
-
-
-
R/W R/W R/W R/W
ADIF WDTIF BITIF SPIF
-
ADDRESS: 0E5H
INITIAL VALUE: 0000 ----B
-
-
-
-
IRQL
MSB
LSB
Serial Communication interrupt request flag
Basic Interval imer interrupt request flag
Watchdog timer interrupt request flag
A/D Conver interrupt request flag
Figure 16-1 Interrupt Request Flag
MAR. 2000 Ver 1.00
71
HYNIX [ HYNIX SEMICONDUCTOR ]
