ORG PIC16CXXX Example

ORG PIC16CXXX Example

Directives highlighted in this example for PIC16CXXX devices are:

• org

Program Functional Description

This example shows the usage of the org directive. Code generation begins at an address spcified by org <address>. The origin of a data table also can be specified by this directive. A data table may be placed either in a program memory region or in an EE data memory region, as in case of PICmicro device with EE data FLASH.

Commented Code Listing

list p=16f877 ;Select the device.

#include <p16f877.inc> ;Include standard header file

;for the selected device.

org 0000 ;The following code will be

;placed in reset address 0.

goto Main ;Jump to an address whose label

;is 'Main'.

org 0004 ;The following code will be

;placed in interrupt address 4.

goto int_routine ;Jump to an address whose label

;is 'int_routine'.

org 0010 ;The following code section will

;placed starting from address 10H.

Main

; ;Write your main program here.

;

;

goto Main ;Loop back to 'Main'.

org 0100 ;The following code section will

;be placed starting from address

;100H.

int_routine

;

; ;Write your interrupt service

; ;routine here.

retfie ;Return from interrupt.

org 1000 ;You can create a data or

;character table starting from

;any address in program memory.

;In this case the address is

;1000h.

ch_tbl1 da "PICwithFLASH" ;6 program memory locations

;(starting from 1000h) will

;be filled with six 14-bit

;packed numbers, each

;representing two 7-bit ASCII

;characters.

org 2100 ;The absolue address 2100h is

;mapped to the 0000 location of

;EE data memory in PIC16Fxxx.

;You can create a data or

;character table starting from

;any address in EE data memory.

ch_tbl2 de "PICwithFLASH" ;12 EE data memory locations

;(starting from 0) will be

;filled with 12 ASCII

;characters.

end