KS57C2308/P2308/C2316/P2316

ADDRESS SPACES

 

 

+PROGRAMMING TIP — Defining Vectored Interrupts

The following examples show you several ways you can define the vectored interrupt and instruction reference areas in program memory:

1.When all vector interrupts are used:

ORG 0000H

VENT0

1,0,RESET

;

EMB 1, ERB 0; Jump to RESET address by RESET

VENT1

0,0,INTB

;

EMB 0, ERB 0; Jump to INTB address by INTB

VENT2

0,0,INT0

;

EMB 0, ERB 0; Jump to INT0 address by INT0

VENT3

0,0,INT1

;

EMB 0, ERB 0; Jump to INT1 address by INT1

VENT4

0,0,INTS

;

EMB 0, ERB 0; Jump to INTS address by INTS

VENT5

0,0,INTT0

;

EMB 0, ERB 0; Jump to INTT0 address by INTT0

2.When a specific vectored interrupt such as INT0, and INTT0 is not used, the unused vector interrupt locations must be skipped with the assembly instruction ORG so that jumps will address the correct locations:

ORG

0000H

 

 

VENT0

1,0,RESET

;

EMB 1, ERB 0; Jump to RESET address by RESET

VENT1

0,0,INTB

;

EMB 0, ERB 0; Jump to INTB address by INTB

ORG

0006H

; INT0 interrupt not used

VENT3

0,0,INT1

;

EMB 0, ERB 0; Jump to INT1 address by INT1

VENT4

0,0,INTS

;

EMB 0, ERB 0; Jump to INTS address by INTS

ORG

000CH

; INTT0 interrupt not used

ORG

0010H

 

 

3.If an INT0 interrupt is not used and if its corresponding vector interrupt area is not fully utilized, or if it is not written by a ORG instruction in Example 2, a CPU malfunction will occur:

ORG 0000H

VENT0

1,0,RESET

;

EMB 1, ERB 0; Jump to RESET address by RESET

VENT1

0,0,INTB

;

EMB 0, ERB 0; Jump to INTB address by INTB

VENT3

0,0,INT1

;

EMB 0, ERB 0; Jump to INT1 address by INT0

VENT4

0,0,INTS

;

EMB 0, ERB 0; Jump to INTS address by INT1

VENT5

0,0,INTT0

;

EMB 0, ERB 0; Jump to INTT0 address by INTS

ORG

0010H

 

 

General-purpose ROM area

In this example, when an INTS interrupt is generated, the corresponding vector area is not VENT4 INTS, but VENT5 INTT0. This causes an INTS interrupt to jump incorrectly to the INTT0 address and causes a CPU malfunction to occur.

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Samsung KS57C2308 manual + Programming TIP Defining Vectored Interrupts