ST72324 STMICROELECTRONICS [STMicroelectronics], ST72324 Datasheet - Page 33

• Manufacturer Part Number: ST72324
• Description: 5V RANGE 8-BIT MCU WITH 8 TO 32K FLASH, 10-BIT ADC, 4 TIMERS, SPI, SCI INTERFACE
• Manufacturer: STMICROELECTRONICS [STMicroelectronics]

INTERRUPTS (Cont’d)
7.3 INTERRUPTS AND LOW POWER MODES
All interrupts allow the processor to exit the WAIT
low power mode. On the contrary, only external
and other specified interrupts allow the processor
to exit from the HALT modes (see column “Exit
from HALT” in “Interrupt Mapping” table). When
several pending interrupts are present while exit-
ing HALT mode, the first one serviced can only be
an interrupt with exit from HALT mode capability
and it is selected through the same decision proc-
ess shown in
Note: If an interrupt, that is not able to Exit from
HALT mode, is pending with the highest priority
when exiting HALT mode, this interrupt is serviced
after the first one serviced.
Figure 19. Concurrent Interrupt Management
Figure 20. Nested Interrupt Management
11 / 10
11 / 10
MAIN
MAIN
Figure
RIM
RIM
18.
IT2
IT2
IT1
IT1
IT4
TRAP
TRAP
IT1
IT4
IT0
IT0
7.4 CONCURRENT & NESTED MANAGEMENT
The following
different interrupt management modes. The first is
called concurrent mode and does not allow an in-
terrupt to be interrupted, unlike the nested mode in
Figure
in this order from the lowest to the highest: MAIN,
IT4, IT3, IT2, IT1, IT0. The software priority is giv-
en for each interrupt.
Warning: A stack overflow may occur without no-
tifying the software of the failure.
IT3
IT3
IT1
20. The interrupt hardware priority is given
IT4
IT2
Figure 19
10
10
SOFTWARE
PRIORITY
LEVEL
SOFTWARE
PRIORITY
LEVEL
MAIN
MAIN
and
3
3
3
3
3
3
3/0
3
3
2
1
3
3
3/0
Figure 20
I1
I1
1 1
1 1
1 1
1 1
1 1
1 1
1 1
1 1
0 0
0 1
1 1
1 1
ST72324
show two
I0
I0
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