#include ; remove this if not necessary #define PRECISION 2 ; byte size for registers M_STOR_STATUS macro WHERE movf STATUS,w movwf WHERE endm M_RETR_STATUS macro WHERE movf WHERE,w movwf STATUS endm cblock 0x20 REG_X:PRECISION REG_Y:PRECISION REG_Z:PRECISION REG_COUNTER REG_STATUS REG_T1 REG_T2 REG_ROT_COUNTER endc org 0x00 goto M_TEST org 0x04 goto M_TEST org 0x0c M_TEST ; Test subroutine movlw REG_X call M_CLR ; clear register X movlw REG_Y call M_CLR ; clear register Y movlw REG_Z call M_CLR ; clear register Z movlw 0x8A movwf REG_X ; set register X (lowest byte) movlw 0xFC movwf REG_Z ; set register Z (lowest byte) call M_ADD ; adds X and Z, result in Z movlw 0x05 ; set regiester X (lowest byte) movwf REG_X call M_DIV ; divide Z by X, result in Y, remainder in Z sleep ; end of test M_CLR ; clear a register movwf FSR movlw PRECISION movwf REG_COUNTER M_CLR_loop clrf INDF incf FSR,f decf REG_COUNTER,f btfss STATUS,Z goto M_CLR_loop return M_INC ; increment a register movwf FSR movlw PRECISION movwf REG_COUNTER M_INC_loop incf INDF,f btfss STATUS,Z return incf FSR,f decf REG_COUNTER,f btfss STATUS,Z goto M_INC_loop return M_DEC ; decrement a register movwf FSR movlw PRECISION movwf REG_COUNTER M_DEC_loop decf INDF,f movlw 0xFF subwf INDF,w btfss STATUS,Z return incf FSR,f decf REG_COUNTER,f btfss STATUS,Z goto M_DEC_loop return M_ROL ; rotate a register to the left movwf FSR M_STOR_STATUS REG_STATUS clrf REG_COUNTER M_ROL_loop M_RETR_STATUS REG_STATUS rlf INDF,f M_STOR_STATUS REG_STATUS incf FSR,f incf REG_COUNTER,f movlw PRECISION subwf REG_COUNTER,w btfss STATUS,Z goto M_ROL_loop return M_ROR ; rotates a register to the right movwf FSR movlw PRECISION-1 addwf FSR,f M_STOR_STATUS REG_STATUS clrf REG_COUNTER M_ROR_loop M_RETR_STATUS REG_STATUS rrf INDF,f M_STOR_STATUS REG_STATUS decf FSR,f incf REG_COUNTER,f movlw PRECISION subwf REG_COUNTER,w btfss STATUS,Z goto M_ROR_loop return M_CMP ; Z <=> X -> STATUS(C,Z) ; STATUS,C set if Z => X; ; STATUS,Z set if Z == X clrf REG_COUNTER M_CMP_loop movf REG_COUNTER,w sublw REG_Z+PRECISION-1 movwf FSR movf INDF,w movwf REG_T1 movf REG_COUNTER,w sublw REG_X+PRECISION-1 movwf FSR movf INDF,w subwf REG_T1,f btfss STATUS,Z return incf REG_COUNTER,f movlw PRECISION subwf REG_COUNTER,w btfss STATUS,Z goto M_CMP_loop return M_ADD ; Z + X -> Z bcf STATUS,C clrf REG_STATUS clrf REG_COUNTER M_ADD_loop clrf REG_T1 btfsc REG_STATUS,C incf REG_T1,f clrf REG_STATUS movlw REG_X addwf REG_COUNTER,w movwf FSR movf INDF,w addwf REG_T1,f btfsc STATUS,C bsf REG_STATUS,C movlw REG_Z addwf REG_COUNTER,w movwf FSR movf INDF,w addwf REG_T1,f btfsc STATUS,C bsf REG_STATUS,C movf REG_T1,w movwf INDF incf REG_COUNTER,f movlw PRECISION subwf REG_COUNTER,w btfss STATUS,Z goto M_ADD_loop return M_SUB ; Z - X -> Z clrf REG_COUNTER bsf REG_STATUS,C M_SUB_loop bsf REG_T2,C movlw REG_Z addwf REG_COUNTER,w movwf FSR movf INDF,w movwf REG_T1 movlw REG_X addwf REG_COUNTER,w movwf FSR movf INDF,w subwf REG_T1,f btfss STATUS,C bcf REG_T2,C btfsc REG_STATUS,C goto M_SUB_no_carry movlw 0x01 subwf REG_T1,f btfss STATUS,C bcf REG_T2,C M_SUB_no_carry movlw REG_Z addwf REG_COUNTER,w movwf FSR movf REG_T1,w movwf INDF bsf REG_STATUS,C btfss REG_T2,C bcf REG_STATUS,C incf REG_COUNTER,f movlw PRECISION subwf REG_COUNTER,w btfss STATUS,Z goto M_SUB_loop btfss REG_STATUS,C bcf STATUS,C return M_MUL ; X * Y -> Z movlw REG_Z call M_CLR movlw PRECISION*8+1 movwf REG_ROT_COUNTER M_MUL_loop decf REG_ROT_COUNTER,f btfsc STATUS,Z return btfsc REG_Y,0 call M_ADD bcf STATUS,C movlw REG_Y call M_ROR bcf STATUS,C movlw REG_X call M_ROL goto M_MUL_loop M_DIV ; Z / X -> Y; remainder -> Z movlw REG_Y call M_CLR movlw PRECISION*8 movwf REG_ROT_COUNTER M_DIV_rot_loop btfsc REG_X+PRECISION-1,7 goto M_DIV_loop movlw REG_X bcf STATUS,C call M_ROL decf REG_ROT_COUNTER,f btfss STATUS,Z goto M_DIV_rot_loop bsf STATUS,Z return M_DIV_loop call M_CMP M_STOR_STATUS REG_T2 movlw REG_Y call M_ROL M_RETR_STATUS REG_T2 btfsc STATUS,C call M_SUB bcf STATUS,Z bcf STATUS,C movlw REG_X call M_ROR incf REG_ROT_COUNTER,f movlw PRECISION*8+1 subwf REG_ROT_COUNTER,w btfss STATUS,Z goto M_DIV_loop return END