Datasheet

173
SAM4S [DATASHEET]
11100E–ATARM–24-Jul-13
12.6.11.10SVC
Supervisor Call.
Syntax
SVC{cond} #imm
where:
cond is an optional condition code, see “Conditional Execution” .
imm is an expression evaluating to an integer in the range 0-255 (8-bit value).
Operation
The SVC instruction causes the SVC exception.
imm is ignored by the processor. If required, it can be retrieved by the exception handler to determine what service is
being requested.
Condition Flags
This instruction does not change the flags.
Examples
SVC 0x32 ; Supervisor Call (SVC handler can extract the immediate value
; by locating it via the stacked PC)
12.6.11.11WFI
Wait for Interrupt.
Syntax
WFI{cond}
where:
cond is an optional condition code, see “Conditional Execution” .
Operation
WFI is a hint instruction that suspends execution until one of the following events occurs:
 An exception
 A Debug Entry request, regardless of whether Debug is enabled.
Condition Flags
This instruction does not change the flags.
Examples
WFI ; Wait for interrupt