s3c4510b Samsung Semiconductor, Inc., s3c4510b Datasheet - Page 135

• Manufacturer Part Number: s3c4510b
• Description: 16/32-bit Risc Microcontroller
• Manufacturer: Samsung Semiconductor, Inc.

S3C4510B
FORMAT 17: SOFTWARE INTERRUPT
OPERATION
The SWI instruction performs a software interrupt. On taking the SWI, the processor switches into ARM state and
enters Supervisor (SVC) mode.
The THUMB assembler syntax for this instruction is shown below.
NOTE: Value 8 is used solely by the SWI handler; it is ignored by the processor.
INSTRUCTION CYCLE TIMES
All instructions in this format have an equivalent ARM instruction as shown in Table 3-24. The instruction cycle
times for the THUMB instruction are identical to that of the equivalent ARM instruction.
Examples
THUMB Assembler
SWI Value 8
15
1
SWI 18
14
1
13
0
ARM Equivalent
12
1
SWI Value 8
11
1
Table 3-24. The SWI Instruction
10
1
Figure 3-46. Format 17
[7:0] Comment Field
9
1
Perform Software Interrupt:
Move the address of the next instruction into LR, move CPSR
to SPSR, load the SWI vector address (0x8) into the PC.
Switch to ARM state and enter SVC mode.
8
1
; Take the software interrupt exception.
; Enter Supervisor mode with 18 as the
; requested SWI number.
7
Value 8
Action
INSTRUCTION SET
0
3-93