INTERRUPT STRUCTURE S3C8275X/F8275X/C8278X/F8278X/C8274X/F8274X

5-2

INTERRUPT TYPES The three components of the S3C8 interrupt structure described before ⎯ levels, vectors, and sources ⎯ are combined to determine the interrupt structure of an individual device and to make full use of its available interrupt logic. There are three possible combinations of interrupt structure components, called interrupt types 1, 2, and 3. The types 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 S3C8275X/C8278X/C8274X 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 S3C8275X/C8278X/C8274X implementation,
interrupt types 1 and 3 are used.
Figure 5-1. S3C8-Series Interrupt Types