ifndef _ad9835_asm #define _ad9835_asm ; define the following in the main program ; for AD9835 SELECT, CLOCK and DATA pins ; ; an example: ; ;#define FSYNC PORTB,0 ;#define SCLK PORTB,1 ;#define SDATA PORTB,2 ;#define FSEL PORTB,3 ;************************************************** ; ; (C) Copyright notice ; ; Written by Richard Prinz. ; Copyright 2003 by Richard Prinz. ; OE1RIB Richard.Prinz@MIN.at ; ; Permission to use, copy, and modify this program ; without restriction is hereby granted, as long as ; ; 1) this copyright notice appears in each copy of ; the program source code and ; ; 2) the source code is not used for commercial ; purposes. ; ; This program is freely distributable without ; licensing fees and is provided without guarantee ; or warrantee expressed or implied. ; ; This program is -not- in the public domain. ; ;************************************************** ;************************************************** ; ; Analog AD9835 DDS Routines ; ;************************************************** Init9835 call Disable9835 ;; 2 call SelectByReg ;; 2 ; select PHASE0 call SelectPhase0 ;; 2 ; clear PHASE0 clrf PHASE_H ;; 2 clrf PHASE_L ;; 2 movlw PHASE0 ;; 1 call SetPhase ;; 2 return ;; 2 ;---------------------------------------------------------------------------- Disable9835 ;; 203 ; sleep, reset, clear bcf DDS_STATUS,ENABLED ;; 1 movlw B'11111000' ;; 1 goto SelectWrite ;; 2+199 ;---------------------------------------------------------------------------- Enable9835 ;; 203 ; enable chip - no sleep, no reset, no clear bsf DDS_STATUS,ENABLED ;; 1 movlw B'11000000' ;; 1 goto SelectWrite ;; 2+199 ;---------------------------------------------------------------------------- SelectByPin ;; 203 ; sync, selsrc (freq & phase) = by register PIN = 0 movlw B'10100000' ;; 1 bcf DDS_STATUS,SELECT_MODE ;; 1 goto SelectWrite ;; 2+199 ;---------------------------------------------------------------------------- SelectByReg ;; 203 ; sync, selsrc (freq & phase) = by register REG = 1 movlw B'10110000' ;; 1 bsf DDS_STATUS,SELECT_MODE ;; 1 goto SelectWrite ;; 2+199 ;---------------------------------------------------------------------------- ;; REG / PIN ToggleFreq ;; 208 / 10 btfss DDS_STATUS,CURRENT_FREQ ;; 1/2 goto SelectFreq1 ;; 2 nop ;; 1 ;; always 3 ;---------------------------------------------------------------------------- ;; REG / PIN SelectFreq0 ;; 205 / 7 ;bcf PORTA,1 ; JUST FOR DEBUGGING bcf DDS_STATUS,CURRENT_FREQ ;; 1 btfss DDS_STATUS,SELECT_MODE ;; 1/2 goto SelectFreq0Pin ;; 2+3 movlw B'01010000' ;; 1 goto SelectWrite ;; 2+199 ;---------------------------------------------------------------------------- SelectFreq0Pin ;; 3 bcf FSEL ;; 1 return ;; 2 ;---------------------------------------------------------------------------- ;; REG / PIN SelectFreq1 ;; 205 / 7 ;bsf PORTA,1 ; JUST FOR DEBUGGING bsf DDS_STATUS,CURRENT_FREQ ;; 1 btfss DDS_STATUS,SELECT_MODE ;; 1/2 goto SelectFreq1Pin ;; 2+3 movlw B'01011000' ;; 1 goto SelectWrite ;; 2+199 ;---------------------------------------------------------------------------- SelectFreq1Pin ;; 3 bsf FSEL ;; 1 return ;; 2 ;---------------------------------------------------------------------------- SelectPhase0 ;; 202 movlw B'01000000' ;; 1 goto SelectWrite ;; 2+199 ;---------------------------------------------------------------------------- SelectPhase1 ;; 202 movlw B'01000010' ;; 1 goto SelectWrite ;; 2+199 ;---------------------------------------------------------------------------- SelectPhase2 ;; 202 movlw B'01000100' ;; 1 goto SelectWrite ;; 2+199 ;---------------------------------------------------------------------------- SelectPhase3 ;; 202 movlw B'01000110' ;; 1 goto SelectWrite ;; 2+199 ;---------------------------------------------------------------------------- SetPhase ;; 408 movwf PHASE_TEMP ;; 1 iorlw B'00011000' ;; 1 movwf DDS_H ;; 1 movf PHASE_L,w ;; 1 movwf DDS_L ;; 1 call Write9835 ; 8 LSB ;; 2+197 movf PHASE_TEMP,w ;; 1 iorlw B'00001001' ;; 1 movwf DDS_H ;; 1 movf PHASE_H,w ;; 1 movwf DDS_L ;; 1 goto Write9835 ; 8 MSB ;; 2+197 ;---------------------------------------------------------------------------- ; ; Update DDS chip with a new frequency word ; ; Note! Since there is no way to update all 32 bits simultaneously ; in the AD9832, we have to toggle between the two frequency ; registers. Example: Load reg0, switch to reg0, load reg1, switch ; to reg1 etc. etc. This is done to prevent glitches occurring when ; two or more bytes change value at the same time. ; (See AD9832 data sheet...) ; ;---------------------------------------------------------------------------- SetFreqEX ;; 824 btfss DDS_STATUS,CURRENT_FREQ ;; 1/2 goto SetFreqEX1 ;; 2 nop ;; 1 ;; always 3 SetFreqEX0 ;; 821 movlw FREQ0 ;; 1 call SetFreq ;; 2+816 goto SelectFreq0 ;; 2 SetFreqEX1 ;; 821 movlw FREQ1 ;; 1 call SetFreq ;; 2+816 goto SelectFreq1 ;; 2 ;---------------------------------------------------------------------------- SetFreq ;; 816 movwf FREQ_TEMP ;; 1 iorlw B'00110000' ; 8L LSB ;; 1 movwf DDS_H ;; 1 movf FREQ_L,w ;; 1 movwf DDS_L ;; 1 call Write9835 ;; 2+197 movf FREQ_TEMP,w ;; 1 iorlw B'00100001' ; 8H LSB ;; 1 movwf DDS_H ;; 1 movf FREQ_M1,w ;; 1 movwf DDS_L ;; 1 call Write9835 ;; 2+197 movf FREQ_TEMP,w ;; 1 iorlw B'00110010' ; 8L MSB ;; 1 movwf DDS_H ;; 1 movf FREQ_M,w ;; 1 movwf DDS_L ;; 1 call Write9835 ;; 2+197 movf FREQ_TEMP,w ;; 1 iorlw B'00100011' ; 8H MSB ;; 1 movwf DDS_H ;; 1 movf FREQ_H,w ;; 1 movwf DDS_L ;; 1 goto Write9835 ;; 2+197 ;---------------------------------------------------------------------------- SelectWrite ;; 199 movwf DDS_H ;; 1 clrf DDS_L ;; 1 Write9835 ;; 197 bcf FSYNC ;; 1 movlw .16 ;; 1 movwf DDS_BIT_TEMP ;; 1 Write9835Loop: ;; 194 btfss DDS_H,7 ;; 1/2 bcf SDATA ;; 1 btfsc DDS_H,7 ;; 1/2 bsf SDATA ;; 1 ;; always 5 bsf SCLK ;; 1 bcf SCLK ;; 1 rlf DDS_L,f ;; 1 rlf DDS_H,f ;; 1 decfsz DDS_BIT_TEMP,f ;; 1/2 goto Write9835Loop ;; 2 bsf FSYNC ;; 1 return ;; 2 ;---------------------------------------------------------------------------- endif