#include "common.inc" global AritBuffer global DecNumber global Multiply global Divide global DivideFraction global ToBCDInteger global ToBCDFraction global TimeBaseAdd global TimeBaseRead udata ; ; Assuming everything fits into bank 0 ; AritBuffer res .17 ; 129 bit Arithmetics Buffer VarA res 1 ; General purpose variable. VarB res 1 ; General purpose variable. VarC res 1 ; General purpose variable. SaveFSR res 1 ; FSR saving place SaveStatus res 1 ; STATUS,IRP saving place DecNumber res .10 ; 20 digit of floating point BCD fraction. One digit 4 bit. code ; This function does not use FSR. ; Non-reentrant, uses VarA, VarB ; ; -> AritBuffer[0]: 4 byte multiplicand ; -> AritBuffer[8]: 4 byte multiplicator ; <- AritBuffer[0]: 8 byte result ; Multiply: swapf STATUS,W BANKSEL SaveStatus movwf SaveStatus ; clear upper 4 byte of result clrf AritBuffer+.4 clrf AritBuffer+.5 clrf AritBuffer+.6 clrf AritBuffer+.7 ; cycle 32 times movlw .32 movwf VarA MultiplyLoop: bcf STATUS,C btfsc AritBuffer,0 ; with a goto instead of call we save stack goto AddMultiply ; it might set carry, which we will add MultiplyBack: rrf AritBuffer+.7,F rrf AritBuffer+.6,F rrf AritBuffer+.5,F rrf AritBuffer+.4,F rrf AritBuffer+.3,F rrf AritBuffer+.2,F rrf AritBuffer+.1,F rrf AritBuffer+0,F decfsz VarA,F goto MultiplyLoop BANKSEL SaveStatus swapf SaveStatus,W movwf STATUS return AddMultiply: ; ; Add AritBuffer[8] to AritBuffer[4] store it in AritBuffer[4], C ; clrf VarB ; Carry ; Byte 0 movf AritBuffer+.8,W addwf AritBuffer+.4,F btfsc STATUS,C bsf VarB,0 ; Byte 1 movf AritBuffer+.9,W addwf VarB,W bcf VarB,0 btfsc STATUS,C bsf VarB,0 addwf AritBuffer+.5,F btfsc STATUS,C bsf VarB,0 ; Byte 2 movf AritBuffer+.10,W addwf VarB,W bcf VarB,0 btfsc STATUS,C bsf VarB,0 addwf AritBuffer+.6,F btfsc STATUS,C bsf VarB,0 ; Byte 2 movf AritBuffer+.11,W addwf VarB,W bcf VarB,0 btfsc STATUS,C bsf VarB,0 addwf AritBuffer+.7,F btfsc STATUS,C bsf VarB,0 ; set carry bcf STATUS,C btfsc VarB,0 bsf STATUS,C goto MultiplyBack Divide: ; This function does not use FSR. ; Non-reentrant, uses VarA, VarB ; ; -> AritBuffer[0]: 8 byte dividend ; -> AritBuffer[8]: 4 byte divisor ; <- AritBuffer[0]: 8 byte quotient ; <- AritBuffer[.12]: 4 byte remainder swapf STATUS,W BANKSEL SaveStatus movwf SaveStatus clrf AritBuffer+.12 clrf AritBuffer+.13 clrf AritBuffer+.14 clrf AritBuffer+.15 goto DivideNoClear DivideFraction: ; This function does not use FSR. ; Non-reentrant, uses VarA, VarB ; ; -> AritBuffer[8]: 4 byte divisor from previous division ; -> AritBuffer[.12]: 4 byte remainder from previous division ; <- AritBuffer[0]: 8 byte binary fraction swapf STATUS,W BANKSEL SaveStatus movwf SaveStatus clrf AritBuffer+.0 clrf AritBuffer+.1 clrf AritBuffer+.2 clrf AritBuffer+.3 clrf AritBuffer+.4 clrf AritBuffer+.5 clrf AritBuffer+.6 clrf AritBuffer+.7 DivideNoClear: ; cycle 64 times movlw .64 movwf VarA DivideLoop: clrf AritBuffer+.16 bcf STATUS,C rlf AritBuffer+.0,F rlf AritBuffer+.1,F rlf AritBuffer+.2,F rlf AritBuffer+.3,F rlf AritBuffer+.4,F rlf AritBuffer+.5,F rlf AritBuffer+.6,F rlf AritBuffer+.7,F ; destination is after divisor rlf AritBuffer+.12,F rlf AritBuffer+.13,F rlf AritBuffer+.14,F rlf AritBuffer+.15,F rlf AritBuffer+.16,F goto SubstactDivide DivideBack: btfsc STATUS,C ; skip borrow bsf AritBuffer,0 decfsz VarA,F goto DivideLoop BANKSEL SaveStatus swapf SaveStatus,W movwf STATUS return SubstactDivide: ; Substract AritBuffer[8] (4bytes) from AritBuffer[12] 4 bytes ; if it can be substracted without borrow. ; return with STATUS,C set if it was substracted. ; Test run. The actual substraction is not taking place now. ; Byte 0 clrf VarB movf AritBuffer+.8,W subwf AritBuffer+.12,W btfss STATUS,C ; Skip not borrow bsf VarB,0 ; Byte 1 movf AritBuffer+.9,W addwf VarB,W clrf VarB btfsc STATUS,C bsf VarB,0 subwf AritBuffer+.13,W btfss STATUS,C ; Skip not borrow bsf VarB,0 ; Byte 2 movf AritBuffer+.10,W addwf VarB,W clrf VarB btfsc STATUS,C bsf VarB,0 subwf AritBuffer+.14,W btfss STATUS,C ; Skip not borrow bsf VarB,0 ; Byte 3 movf AritBuffer+.11,W addwf VarB,W clrf VarB btfsc STATUS,C bsf VarB,0 subwf AritBuffer+.15,W btfss STATUS,C ; Skip not borrow bsf VarB,0 btfss VarB,0 ; Skip Borrow goto DivideNoborrow bcf STATUS,C ; Borrow btfss AritBuffer+.16,0; There is one more bit goto DivideBack DivideNoborrow: ; Real substract - everything is same except F instead of W ; Byte 0 clrf VarB movf AritBuffer+.8,W subwf AritBuffer+.12,F btfss STATUS,C ; Skip not borrow bsf VarB,0 ; Byte 1 movf AritBuffer+.9,W addwf VarB,W clrf VarB btfsc STATUS,C bsf VarB,0 subwf AritBuffer+.13,F btfss STATUS,C ; Skip not borrow bsf VarB,0 ; Byte 2 movf AritBuffer+.10,W addwf VarB,W clrf VarB btfsc STATUS,C bsf VarB,0 subwf AritBuffer+.14,F btfss STATUS,C ; Skip not borrow bsf VarB,0 ; Byte 3 movf AritBuffer+.11,W addwf VarB,W clrf VarB btfsc STATUS,C bsf VarB,0 subwf AritBuffer+.15,F btfss STATUS,C ; Skip not borrow bsf VarB,0 bsf STATUS,C ; Not borrow. Borrow already returned goto DivideBack ToBCDInteger: ; Convert binary integer to BCD ; -> AritBuffer[0]: 8 byte binary integer (AritBuffer[0] LSB) ; <- DecNumber BCD integer ; The algo uses shift right (multiply by 2) operation ; to shift out binary and shift in BCD. swapf STATUS,W BANKSEL SaveStatus movwf SaveStatus movf FSR,W movwf SaveFSR bcf STATUS,IRP ; FSR bank 0,1 ; ; Clear DecNumber buffer ; movlw .10 movwf VarA movlw DecNumber movwf FSR ToBCDIntegerLoop1: clrf INDF incf FSR,F decfsz VarA,F goto ToBCDIntegerLoop1 ; Shift out all 8 bytes from AritBuffer[7] into ; Decbuffer[0]..Decbuffer[.19] movlw .64 ; number of bits movwf VarA ToBCDIntegerLoop2 bcf STATUS,C rlf AritBuffer+.0,F rlf AritBuffer+.1,F rlf AritBuffer+.2,F rlf AritBuffer+.3,F rlf AritBuffer+.4,F rlf AritBuffer+.5,F rlf AritBuffer+.6,F rlf AritBuffer+.7,F ; Shift carry into DecNumber[0-.19] decimally, multiplying by 2 movlw .10 ; 20 nibbles = 10 bytes movwf VarB movlw DecNumber movwf FSR ToBCDIntegerLoop3 clrf VarC btfsc STATUS,C bsf VarC,0 ; carry in VarC LSB ; Prepare for BCD multiply 2 via shift movf INDF,W addlw H'0b' ; test 5 or greater become 0 or greater btfsc STATUS,DC ; add 3 to it addlw H'3' addlw -H'0b' ; restore addlw H'0b0' ; test 50 or greater become 0 or greater btfsc STATUS,C ; add 30 to it addlw H'30' addlw -H'0b0' ; restore movwf INDF bcf STATUS,C btfsc VarC,0 bsf STATUS,C rlf INDF,F incf FSR,F decfsz VarB,F goto ToBCDIntegerLoop3 decfsz VarA,F goto ToBCDIntegerLoop2 ; Restore FSR movf SaveFSR,W movwf FSR BANKSEL SaveStatus swapf SaveStatus,W movwf STATUS return ToBCDFraction: ; Convert binary fraction to BCD ; -> AritBuffer[0]: 8 byte binary fraction (AritBuffer[0] LSB) ; <- DecNumber[0] .10 byte BCD fraction DecNumber[.9] MSB ; The algo uses shift left (divide by 2) operation ; to shift out binary and shift in BCD. ; for instance, 0.125 = DecNumber[.8]= 05, DecNumber[.9] = 21 swapf STATUS,W BANKSEL SaveStatus movwf SaveStatus movf FSR,W movwf SaveFSR bcf STATUS,IRP ; FSR bank 0,1 ; ; Clear DecNumber buffer ; movlw .10 movwf VarA movlw DecNumber movwf FSR ToBCDFractionLoop1: clrf INDF incf FSR,F decfsz VarA,F goto ToBCDFractionLoop1 ; Shift out all 8 bytes from AritBuffer[7] into ; Decbuffer[0]..Decbuffer[.19] movlw .64 ; number of bits movwf VarA ToBCDFractionLoop2 bcf STATUS,C rrf AritBuffer+.7,F rrf AritBuffer+.6,F rrf AritBuffer+.5,F rrf AritBuffer+.4,F rrf AritBuffer+.3,F rrf AritBuffer+.2,F rrf AritBuffer+.1,F rrf AritBuffer+.0,F ; Shift carry into DecNumber[0-.19] decimally, multiplying by 2 movlw .10 ; 20 nibbles = 10 bytes movwf VarB movlw DecNumber+.9 movwf FSR ToBCDFractionLoop3 rrf INDF,F clrf VarC btfsc STATUS,C bsf VarC,0 ; carry in VarC LSB ; Prepare for BCD divison by 2 via shift movf INDF,W btfsc INDF,7 ; test if 80 came in addlw -H'30' ; substract 30 btfsc INDF,3 ; test if 8 came in addlw -H'3' ; substract 3 movwf INDF bcf STATUS,C btfsc VarC,0 bsf STATUS,C decf FSR,F decfsz VarB,F goto ToBCDFractionLoop3 decfsz VarA,F goto ToBCDFractionLoop2 ; Restore FSR movf SaveFSR,W movwf FSR BANKSEL SaveStatus swapf SaveStatus,W movwf STATUS return TimeBaseAdd: ; Add W to current timebase that is stored in EEPROM ; W can be negative. BANKSEL VarA movwf VarA ; Read data into AritBuffer movlw 0 call TimeBaseRead BANKSEL AritBuffer movwf AritBuffer+0 movlw 1 call TimeBaseRead BANKSEL AritBuffer movwf AritBuffer+1 movlw 2 call TimeBaseRead BANKSEL AritBuffer movwf AritBuffer+2 movlw 3 call TimeBaseRead BANKSEL AritBuffer movwf AritBuffer+3 ; Add W into aritbuffer movf VarA,W btfsc VarA,7 goto TimeBaseSub ; Add addwf AritBuffer,F btfss STATUS,C goto TimeBaseAddDone movlw 1 addwf AritBuffer+1,F btfss STATUS,C goto TimeBaseAddDone addwf AritBuffer+2,F btfss STATUS,C goto TimeBaseAddDone addwf AritBuffer+3,F goto TimeBaseAddDone TimeBaseSub: ; Substract addwf AritBuffer,F btfsc STATUS,C ; Skip BORROW goto TimeBaseAddDone movlw -1 addwf AritBuffer+1,F btfsc STATUS,C goto TimeBaseAddDone addwf AritBuffer+2,F btfsc STATUS,C goto TimeBaseAddDone addwf AritBuffer+3,F ; goto TimeBaseAddDone TimeBaseAddDone: movlw 0 call TimeBaseWriteByte movlw 1 call TimeBaseWriteByte movlw 2 call TimeBaseWriteByte movlw 3 call TimeBaseWriteByte return TimeBaseWriteByte: ; Write AritBuffer[W] to EEPROM[W] BANKSEL EEADR movwf EEADR ; Address to write BANKSEL VarA movwf VarA ; Same bank as SaveFSR movf FSR,W movwf SaveFSR movf VarA,W addlw AritBuffer movwf FSR bcf STATUS,IRP ; FSR bank 0,1 ; Write bytes movf INDF,W BANKSEL EEDATA movwf EEDATA ; Data to write BANKSEL SaveFSR movf SaveFSR,W movwf FSR BANKSEL EECON1 bcf EECON1,EEPGD ; Point to data memory bsf EECON1,WREN ; Enable write ; Disable interrups BANKSEL INTCON bcf INTCON,GIE BANKSEL EECON2 movlw h'55' movwf EECON2 ; Assume EECON2 is same bank as EECOM1 movlw h'AA' movwf EECON2 ; Assume EECON2 is same bank as EECOM1 bsf EECON1,WR ; Enable interrupts BANKSEL INTCON bsf INTCON,GIE bcf EECON1,WREN ; Disable write BANKSEL EECON1 TimeBaseWait1: btfsc EECON1,WR ; Wait for preveious write to complete goto TimeBaseWait1 return TimeBaseRead: ; Read TimeBase at W. 0 is LSB. ; return byte in W BANKSEL EEADR movwf EEADR ; Address to read BANKSEL EECON1 bcf EECON1,EEPGD ; Point to data memory bsf EECON1,RD ; EEprom read BANKSEL EEDATA movf EEDATA,W BANKSEL AritBuffer ; Select page 0 return org 0x2100 ; EEPROM area ; ; This is the CPLD reference clock frequency ; 9953280 => 97E000 ; When measure it was: 9953280 * 1.00000350 = 9953314 ; ; LSB first ERRORLEVEL -220 ; Address exceeds maximum range for this processor ; de 0x00, 0xe0, 0x97, 0x00 ; 27MHz = 19BFCC0 ; de 0xc0, 0xfc, 0x9b, 0x01 ; 100MHz = 5F5E100 de 0x00, 0xe1, 0xf5, 0x05 de 'S', 'i', 'n', 'a', 'i', ' ' de 'G', 'a', 's', 'p', 'a', 'r', '\n' de 'e', 'm', 'a', 'i', 'l', ':' de 'g', 'a', 's', 'p', 'a', 'r' de '@', 'y', 'u', 'd', 'i', 't' de '.', 'o', 'r', 'g', '\n' de 'Y', 'u', 'p', 'r', 'a', '\n' de 'v', '1', '.', '0', '.', '0', '\n' de '2', '0', '1', '0', '-', '0', '5', '-', '2', '3', '\n' de 'T', 'o', 'k', 'y', 'o', '\n' de 0x00 end