
S3C8248/C8245/P8245/C8247/C8249/P8249
INTERRUPT STRUCTURE
5-3
S3C8248/C8245/C8247/C8249 INTERRUPT STRUCTURE
The S3C8248/C8245/C8247/C8249 microcontroller supports sixteen interrupt sources. All sixteen of the interrupt
sources have a corresponding interrupt vector address. Eight interrupt levels are recognized by the CPU in this
device-specific interrupt structure, as shown in Figure 5-2.
When multiple interrupt levels are active, the interrupt priority register (IPR) determines the order in which
contending interrupts are to be serviced. If multiple interrupts occur within the same interrupt level, the interrupt
with the lowest vector address is usually processed first (The relative priorities of multiple interrupts within a
single level are fixed in hardware).
When the CPU grants an interrupt request, interrupt processing starts. All other interrupts are disabled and the
program counter value and status flags are pushed to stack. The starting address of the service routine is fetched
from the appropriate vector address (plus the next 8-bit value to concatenate the full 16-bit address) and the
service routine is executed.
Vectors
Sources
Levels
Reset/Clear
NOTES:
1. Within a given interrupt level, the low vector address has high priority.
For example, E0H has higher priority than E2H within the level IRQ.0 the priorities within each
level are set at the factory.
2. External interrupts are triggered by a rising or falling edge, depending on the corresponding control
register setting.
IRQ3
E8H
Timer 1 match/capture
EAH
Timer 1 overflow
Timer B match
E4H
Timer 0 match
E6H
IRQ1
IRQ2
H/W
SIO interrupt
ECH
Watch timer overflow
EEH
IRQ4
IRQ5
P0.0 external interrupt
P0.1 external interrupt
P0.2 external interrupt
P0.3 external interrupt
IRQ6
F0H
F2H
F4H
F6H
P0.4 external interrupt
P0.5 external interrupt
P0.6 external interrupt
P0.7 external interrupt
IRQ7
F8H
FAH
FCH
FEH
E0H
Timer A match/capture
IRQ0
E2H
Timer A overflow
H/W,S/W
H/W,S/W
H/W,S/W
H/W,S/W
H/W,S/W
S/W
S/W
S/W
S/W
S/W
S/W
S/W
S/W
S/W
S/W
Figure 5-2. S3C8248/C8245/C8247/C8249 Interrupt Structure
Summary of Contents for C8245
Page 31: ...ADDRESS SPACES S3C8248 C8245 P8245 C8247 C8249 P8249 2 20 NOTES ...
Page 107: ...INTERRUPT STRUCTURE S3C8248 C8245 P8245 C8247 C8249 P8249 5 18 NOTES ...
Page 195: ...INSTRUCTION SET S3C8248 C8245 P8245 C8247 C8249 P8249 6 88 NOTES ...
Page 221: ...I O PORTS S3C8248 C8245 P8245 C8247 C8249 P8249 9 16 NOTES ...
Page 245: ...16 BIT TIMER 0 1 S3C8248 C8245 P8245 C8247 C8249 P8249 12 10 NOTES ...
Page 249: ...WATCH TIMER S3C8248 C8245 P8245 C8247 C8249 P8249 13 4 NOTES ...
Page 267: ...A D CONVERTER S3C8248 C8245 P8245 C8247 C8249 P8249 15 6 NOTES ...
Page 299: ...S3P8245 P8249 OTP S3C8248 C8245 P8245 C8247 C8249 P8249 21 8 NOTES ...
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