SW500009 Microchip Technology, SW500009 Datasheet - Page 77

• Manufacturer Part Number: SW500009
• Description: HI-TECH FOR DSPIC/PIC24
• Manufacturer: Microchip Technology
• Type: Compilerr
• Series: PIC24 & DsPICr

Specifications of SW500009

• Supported Families: PIC24
• Core Architecture: PIC, DsPIC
• Software Edition: Standard
• Kit Contents: Software And Docs
• Tool Type: Compiler
• Mcu Supported Families: PIC24 MCUs And DsPIC DSCs
• Lead Free Status / RoHS Status: Not applicable / RoHS Compliant
• For Use With/related Products: DSPIC3X/PIC24
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant
• Other names: 025; 778-1003; 778-1003

C Language Features
As there is a maximum of one interrupt vector in the midrange PIC series, only one interrupt
function may be defined. The interrupt vector will automatically be set to point to this function.
3.10.1.2 Highend Interrupt Functions
As there is more than one vector location usable with highend processors, an indicator is required
with the function definition to specify the interrupt vector to which the function should associated.
This takes the form of a @ symbol followed by the vector address at the end of the function prototype.
3.10.1.3 Context Saving on Interrupts
The PIC processor only saves the PC on its stack whenever an interrupt occurs. Other registers and
objects must be saved in software. The PICC compiler determines which registers and objects are
used by an interrupt function and saves these appropriately.
code in the same module, then any registers used by these functions will be saved as well. If the
called functions have not been seen by the compiler, a worst case scenario is assumed and all registers
and objects will be saved.
register usage. Thus, if you include in-line assembly code into an interrupt function, you may have
to add extra assembly code to save and restore any registers or locations used.
3.10.1.4 MidRange Context Saving
The code associated with interrupt functions that do not require registers or objects is placed directly
at the interrupt vector in a psect called intcode.
An example of an interrupt function for a high-end processor is shown here.
If the interrupt routine calls other functions and these functions are defined before the interrupt
PICC does not scan assembly code which is placed in-line within the interrupt function for
}
int tick_count;
void interrupt tc_int(void) @ 0x10
{
}
}
if (TMR0IE && T0IF) {
}
++tick_count;
T0IF = 0;
++tick_count;
Interrupt Handling in C
63