INTERRUPT STRUCTURE S3C8245/P8245/C8249/P8249

5-2

INTERRUPT TYPESThe three components of the S3C8 interrupt structure described before — levels, vectors, and sources — arecombined to determine the interrupt structure of an individual device and to make full use of its available interruptlogic. There are three possible combinations of interrupt structure components, called interrupt types 1, 2, and 3. Thetypes differ in the number of vectors and interrupt sources assigned to each level (see Figure 5-1):Type 1: One level (IRQn) + one vector (V1) + one source (S1)Type 2: One level (IRQn) + one vector (V1) + multiple sources (S1 – Sn)Type 3: One level (IRQn) + multiple vectors (V1 – Vn) + multiple sources (S1 – Sn , Sn+1 – Sn+m)In the S3C8245/C8249 microcontroller, two interrupt types are implemented.
Vectors SourcesLevels
S
1
V
1
S
2
Type 2:
IRQn
S
3
S
n
V
1
S
1
V
2
S
2
Type 3:
IRQn
V
3
S
3
V
1
S
1
Type 1:
IRQn
V
n
S
n +
1
S
n
S
n +
2
S
n +
m
NOTES:
1. The number of S
n
and V
n
value is expandable.
2. In the S3C8245/C8249 implementation,
interrupt types 1 and 3 are used.
Figure 5-1. S3C8-Series Interrupt Types