SW500008 Microchip Technology, SW500008 Datasheet - Page 83

• Manufacturer Part Number: SW500008
• Description: PICC-18 STD
• Manufacturer: Microchip Technology
• Type: Compilerr
• Series: PIC18r

Specifications of SW500008

• Supported Families: PIC18
• Core Architecture: PIC
• Software Edition: Standard
• Kit Contents: Software And Docs
• Mcu Supported Families: PIC18
• Tool Function: Compiler
• Tool Type: Compiler
• Lead Free Status / RoHS Status: Not applicable / RoHS Compliant
• For Use With/related Products: PIC18 Series
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant
• Other names: 015; 778-1001; 778-1001

C Language Features
3.11 Mixing C and Assembler Code
Assembly language code can be mixed with C code using three different techniques.
3.11.1 External Assembly Language Functions
Entire functions may be coded in assembly language as separate .as source files, assembled by the
assembler (ASPIC18) and combined into the binary image using the linker. This technique allows
arguments and return values to be passed between C and assembler code.
that is callable from C code.
A mapping is performed on the names of all C functions and non-static global variables. See
3.11.2
The following are guidelines that must be adhered to when writing a routine in assembly code
}
select, or define, a suitable psect for the executable assembly code
select a name (label) for the routine so that its corresponding C identifier is valid
ensure that the routine’s label is globally accessable from other modules
select an appropriate equivalent C prototype for the routine on which argument passing can be
modelled
ensure any symbol used to hold arguments to the routine is globally accessable
ensure any symbol used to hold a return value is globally accessable
optionally, use a signature value to enable type checking when the function is called
write the routine ensuring arguments are read from the correct location, the return value is
loaded to the correct storage location before returning
ensure any local variables required by the routine have space reserved by the appropriate
directive
for a description of mappings between C and assembly identifiers.
}
PORTB;
RBIF = 0; // clear event flag
// process interrupt here
// Read PORTB to clear any mismatch
Mixing C and Assembler Code
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