Epson S5U1C17001C, Manual

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4-4
EPSOn
S5U1C17001C ManUal
(C COMPilEr PaCkagE fOr S1C17 faMily) (Ver. 1.5.0)
4 SOUrCE filES
4.2.3 in-line assemble
The
xgcc
C compiler supports in-line assembly, so the
asm
statement can be used. As a result, the word "
asm
" is
reserved for system use.
Format:
asm("
<character string>
");
Example 1:
/* HALT mode */
asm("halt");
Example 2:
/* Trap Table*/
asm(".long BOOT\n\
.long ADDR_ERR\n\
.long NMI\n\
.space 4\n\
.long EINT0\n\
.long EINT1");
Example 3:
BOOT(){
asm("xld.a %sp,0x3f00"); /* set SP */
:
}
For details on how to write an assembly source, refer to Section 4.3, "Grammar of Assembly Source".
4.2.4 Prototype Declarations
Declaring interrupt handler functions
Interrupt handler functions should be declared in the following format:
<type> <function name>
__attribute__ ((interrupt_handler));
Example:
void foo(void) __attribute__ ((interrupt_handler));
int int_num;
void foo()
{
int_num = 5;
}
Assembler code
foo:
ld.a -[%sp],%r2
ld %r2,5
xld [int_num],%r2
ld.a %r2,[%sp]+
reti