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UPD78F0411GA-GAM-AX Datasheet, PDF (444/564 Pages) Renesas Technology Corp – Old Company Name in Catalogs and Other Documents | |||
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CHAPTER 17 INTERRUPT FUNCTIONS
Cautions 3. When manipulating a flag of the interrupt request flag register, use a 1-bit memory
manipulation instruction (CLR1). When describing in C language, use a bit manipulation
instruction such as âIF0L.0 = 0;â or â_asm(âclr1 IF0L, 0â);â because the compiled assembler
must be a 1-bit memory manipulation instruction (CLR1).
If a program is described in C language using an 8-bit memory manipulation instruction such
as âIF0L &= 0xfe;â and compiled, it becomes the assembler of three instructions.
mov a, IF0L
and a, #0FEH
mov IF0L, a
In this case, even if the request flag of another bit of the same interrupt request flag register
(IF0L) is set to 1 at the timing between âmov a, IF0Lâ and âmov IF0L, aâ, the flag is cleared to
0 at âmov IF0L, aâ. Therefore, care must be exercised when using an 8-bit memory
manipulation instruction in C language.
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Userâs Manual U18698EJ1V0UD
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