freq32.asm

frequence metre to mesure the frequence of a signal

;_______________________________________________________________________________
; Program       : "FREQLCD.ASM"
; Date          : 6/11/98                       Last update : 08/05/99
; Description   : Fr俼uencem妕re 50 MHz
;
; Authors       : Loic LEFEBVRE 
; Tests         :
;_______________________________________________________________________________
;
;_________________________________directives____________________________________

           title      "Fr俼uencem妕re 50 MHz V1.00"
           processor  16F84
           include    p16f84.inc
           __config   _PWRTE_OFF & _WDT_OFF & _XT_OSC
           radix      DEC
           errorlevel -302
           include    macros.lib
		  

;___________________________________Constants_______________________________

RAM        equ        h'0C'     
YES        equ        1
NO         equ        0

;______________________________Port configuration___________________________
;
;PORTA
;-----
; A_0      (Out)      = E (afficheur LCD)
; A_1      (Out)      = RS (afficheur LCD)
; A_2      (Out)      = Power control
; A_3      (Out)      = Hardware stop 
; A_4      (In)       = Signal in
;                       xxx43210
CONFIGA    equ        B'00010000'

;Port B
;------
; B_0      (In)       = 
; B_1      (In)       = 
; B_2      (In)       =
; B_3      (In)       =
; B_4      (Out)      = |
; B_5      (Out)      = | Bus de donn俥 (en sortie lors du reset)
; B_6      (Out)      = |
; B_7      (Out)      = |
;                       76543210
CONFIGB    equ        B'00001111'
PULLUP     equ        NO


;____________________________ registers configuration_______________________
									    
;OPTION
;======
;RBPU/  : 0           Enable pull-ups resistors in port B  
;INTEDG : x           Interrupt edge select bit       
;TOCS   : 1           TMRO increment source on RA4/TOCKI pin 
;TOSE   : 0           TMR0 increment on rising RA4/TOCKI pin 
;PSA    : 0           Prescaler assignment bit (to TMR0)
;PS2    : 1           |
;PS1    : 1           |Ratio of 1/256
;PS0    : 1           |

CONFOPT    equ        B'00100111' 


;INTERRUPTION
;============
;GIE    :0            Global interrupt enable bit
;EEIE   :0            EE write complete interrupt enable bit
;T0IE   :0            TMR0 overflow interrupt enable bit
;INTE   :0            RB0/INT interrupt enable bit
;RBIE   :0            RB port change interrupt enable bit
;T0IF   :0            TMR0 overflow interrupt flag bit
;INTF   :0            RB0/INT interrupt flag bit
;RBIF   :0            RB port change interrupt flag bit

CONFINT    equ        B'00000000'

;_________________________________Some Define_______________________________

#define    E                     PORTA,0
#define    RS                    PORTA,1
#define    DATA_PORT             PORTB      ; Seulement de RB7