PIC18F2585/2680/4585/4680

DS80202G-page 6

© 2007 Microchip Technology Inc.

EXAMPLE 3:

An optimized C18 version is provided in

Example 4.

This example illustrates how it reduces the

instruction cycle count from 10 cycles to 3.

Date Codes that pertain to this issue:

All engineering and production devices.

EXAMPLE 4:

#pragma interruptlow MyLowISR

void MyLowISR(void)

{

// Handle low priority interrupts.

}

// Although MyHighISR is a high priority interrupt, use interruptlow pragma so that

// the compiler will not use retfie FAST.

#pragma interruptlow MyHighISR

void MyHighISR(void)

{

// Handle high priority interrupts.

}

#pragma code highVector=0x08

void HighVector (void)

{

_asm goto MyHighISR _endasm

}

#pragma code /* return to default code section */

#pragma code lowVector=0x18

void LowVector (void)

{

_asm goto MyLowISR _endasm

}

#pragma code /* return to default code section */

#pragma code high_vector_section=0x8

void high_vector (void)

{

_asm

CALL high_vector_branch, 1

_endasm

}

void high_vector_branch (void)

{

_asm

POP

GOTO high_isr

_endasm

}

#pragma interrupt high_isr

void high_isr (void)

{

...

}