;;
  ;;  mur.sat
  ;;
  ;;  Somewhen in the year 2011, mur.at will have a nano satellite launched
  ;;  into a low earth orbit (310 km above the surface of our planet). The
  ;;  satellite itself is a TubeSat personal satellite kit, developed and
  ;;  launched by interorbital systems. mur.sat is a joint venture of mur.at,
  ;;  ESC im Labor and realraum.
  ;;
  ;;  Please visit the project hompage at sat.mur.at for further information.
  ;; 
  ;;
  ;;  Copyright (C) 2011 Christian Pointner <equinox@mur.at>
  ;;                         
  ;;  This file is part of mur.sat.
  ;;
  ;;  mur.sat is free software: you can redistribute it and/or modify
  ;;  it under the terms of the GNU General Public License as published by
  ;;  the Free Software Foundation, either version 3 of the License, or
  ;;  any later version.
  ;;
  ;;  mur.sat is distributed in the hope that it will be useful,
  ;;  but WITHOUT ANY WARRANTY; without even the implied warranty of
  ;;  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  ;;  GNU General Public License for more details.
  ;;
  ;;  You should have received a copy of the GNU General Public License
  ;;  along with mur.sat. If not, see <http://www.gnu.org/licenses/>.
  ;;
  ;; -------------------------------------
  ;; PREAMBLE

  LIST      p=16F887
  include   "p16f887.inc"
  ;; TODO: set correct configuration bits
  __config _DEBUG_OFF & _LVP_OFF & _FCMEN_OFF & _IESO_OFF & _BOR_OFF & _CPD_OFF & _CP_OFF & _MCLRE_OFF & _PWRTE_OFF & _WDT_OFF & _XT_OSC
  
  
  ;; -------------------------------------
  ;; DEFINES
  ;;   constants
  
  ;;   I/O Pins
LED         EQU 5

  ;;   variables
  ;;     page 0 only
CNT0        EQU H'0020'
CNT1        EQU H'0021'

  ;;     all pages
W_TEMP      EQU H'007E'
STATUS_TEMP EQU H'007F'

  ;;    bits 
  
  ;; -------------------------------------
  ;; Reset Vector
  org	      0
  goto      init

  ;; -------------------------------------
  ;; Interrupt Vector
  org	      4
  ;; save context
  movwf     W_TEMP
  swapf     STATUS,W
  movwf     STATUS_TEMP

  bcf       STATUS,RP0
  bcf       STATUS,RP1

  ;; TODO: implement interrupt service routines
  
interrupt_end
  ;; restore context
  swapf     STATUS_TEMP,W
  movwf     STATUS
  swapf     W_TEMP,F
  swapf     W_TEMP,W
  retfie

  ;; -------------------------------------
  ;; INIT
init
    ;; bank 1
  bsf       STATUS,RP0
  bcf       STATUS,RP1

  movlw     b'11000111'
  movwf     OPTION_REG
  clrf      PSTRCON
  movlw     b'00010000'
  movwf     OSCCON
  movlw     b'11011111'
  movwf     TRISD
  bcf       STATUS,RP0  

  ;; bank 0
  bsf       PORTD,LED
  clrf      TMR0  

  goto      main

  ;; -------------------------------------
  ;; TABLES

  ;; TODO: add lookup tables if needed
  
  ;; -------------------------------------
  ;; SUBROUTINES

  ;; TODO: add subroutines
  
  ;; -------------------------------------
  ;; MAINLOOP
main
  bcf       INTCON,T0IF
loop 
  btfss     INTCON,T0IF
  goto      loop

  movlw     b'00100000'
  xorwf     PORTD,f
  goto      main
  
powerdown
  sleep
  nop
  goto      main
  
  ;; -------------------------------------
  ;; END
  end