; Chapter 11 6812 assembly language programs
; Jonathan W. Valvano, 2/26/07
; This software accompanies the book,
; Embedded Microcomputer Systems: Real Time Interfacing, Second Edition
; published by Thomson Engineering, 2006



; MC9S12C32
; Analog signal connected to PAD7-0
ADC_Init movb  #$80,ATDCTL2 ;power up
         movb  #$05,ATDCTL4 ;10-bit
         rts    
;In:  RegA has channel Number
;Out: RegD has ADC result
ADC_In   staa  ATDCTL5 ;Start ADC 
Loop     brclr ATDSTAT,$80,Loop  
         ldd   ATDDR0  ;first result
         rts
; Program 11.12. Assembly software to sample data using the ADC.




;***********************old programs from first edition**********


;  Program 11.16. Assembly software to sample data using the A/D (fixed channel).
; MC68HC812A4/MC68HC912B32
; Analog signal connected to PAD1
;ATDCTL5 Register ($0065)
;   7  0     Not implemented
;   6  S8CM=0     4 conversions
;   5  SCAN =0    one set of 4 
;   4  MULT =0    single channel
;  3-0 CD-A =0001 Mux addr PAD1
Init ldaa  #$80    ;Turn on A/D
     staa  ATDCTL2 ;A/D power up
     rts           ;E clk timing
Samp ldaa  #1
     staa  ATDCTL5 ;Start A/D
Loop brclr ATDSTAT,$80,Loop  
     ldaa  ADR0H  ;first result
     rts

;  Program 11.17. Assembly software to sample data using the A/D (variable channel).
; MC68HC812A4/MC68HC912B32
; Analog signal connected to PAD7-0
;ATDCTL5 Register ($0065)
;   7  0     Not implemented
;   6  S8CM=0     4 conversions
;   5  SCAN =0    one set of 4 
;   4  MULT =0    single channel
;  3-0 CD-A =0001 Mux addr PAD7-0
Init ldaa  #$80    ;Turn on A/D
     staa  ATDCTL2 ;A/D power up
     rts           ;E clk timing
A2D  staa  ATDCTL5 ;Start A/D
Loop brclr ATDSTAT,$80,Loop  
     ldaa  ADR0H  ;first result
     rts

;