@LIB_NAME OneWire

@LIB_NOTES 

@LIB_SHARED
' Code and data shared by more than one subroutine in this library
@LOCAL
' Add Local (non-persistent) variables here
@CODE
' Add any shared code here.....
@END

@MACRO_START OWCRC

@TARGET 16 Bit

OWCRC MACRO  P1, P2 
#IF (PRM_COUNT > 2) 
 #ERROR "OWCRC - Too many parameters" 
#ELSE 
 #IF (PRM_COUNT < 2) 
  #ERROR "OWCRC - Too few parameters" 
 #ELSE 
  #IF(PRM_1 != BYTE_ARRAY_PTR) 
   #ERROR "OWCRC - OW_DATA(Param1) Should be a BYTE array pointer" 
  #ENDIF 
  #IF(PRM_2 != Byte) && (PRM_2 != NUM8) && (PRM_2 != NUM16) && (PRM_2 != NUM32) 
   #ERROR "OWCRC - OW_LEN(Param2) Should be a Byte variable or number" 
  #ENDIF 
  #IF (PRM_1 == BYTE_ARRAY_PTR) 
 @  NUM_FSR1 P1 
  #ENDIF 
  #IF (PRM_2 == Byte) 
   BYTE_BYTE P2, OW_Len 
  #ENDIF 
  #IF (PRM_2 == NUM8) 
   NUM_BYTE P2, OW_Len 
  #ENDIF 
  #IF (PRM_2 == NUM16) 
   NUM_BYTE P2, OW_Len 
  #ENDIF 
  #IF (PRM_2 == NUM32) 
   NUM_BYTE P2, OW_Len 
  #ENDIF 
  GoSub Get_OW_Calc 
 #ENDIF 
 #IF (OWCRC_RETURN != 1) 
  #ERROR "OWCRC - Mandatory return parameter misssing" 
 #ELSE 
  #IF(RETURN_TYPE !=Byte) && (RETURN_TYPE !=Word) && (RETURN_TYPE !=DWord) 
   #ERROR "OWCRC - Return variable should be a Byte variable or number" 
  #ELSE 
   #IF (RETURN_TYPE == Byte) 
    BYTE_BYTE OW_CRC_Calc, RETURN_VAR 
   #ENDIF 
  #ENDIF 
 #ENDIF 
#ENDIF 
ENDM 

@LOCAL
'Add Local (non-persistent) variables here
Dim OW_CRC_Calc As Byte
Dim OW_Len As Byte
Dim OW_Byte_Ptr As Byte
Dim OW_TmpDat As Byte
Dim OW_Idx As Byte
Dim OW_TestByte As Byte

@CODE

Get_OW_Calc:
    OW_CRC_Calc = 0								            ' Set up initial CRC value
	For OW_Byte_Ptr = 0 To OW_Len -1   		   	 	' Run through all the data bytes
	   OW_TmpDat = POSTINC1                     ' Get the next data byte
ASM
				movlw 8
				movwf OW_Idx 													; Do this for all 8 bits of CRCByte
		OW_CRCLOOP
				movf OW_CRC_Calc,0 									  ; Put CRC into W
				xorwf OW_TmpDat,0 										; XOR CRC with CRCData
				movwf OW_TestByte 										; Put results in TestByte
				rrcf OW_TestByte,1 										; Shift TestByte.0 into Carry bit
				btfss STATUS,C 												; If Carry = 1, account for EXOR feedback gates
				GoTo OW_CRCSHIFT 											; Otherwise just shift CRC and CRCByte
				movf OW_CRC_Calc,0 										; Get latest copy of CRC
				xorlw 0x18 														; XOR with 18Hex
				movwf OW_CRC_Calc 										; Keep a copy of results
		OW_CRCSHIFT
				rrcf OW_CRC_Calc,1 									  ; Rotate CRC incorporating carry
				rrcf OW_TmpDat,1 											; Rotate CRCData, carry shifts in but not important
				decfsz OW_Idx,1 											; Keep track of #times through loop
				GoTo OW_CRCLOOP 											; back to start if not done all 8 bits
ENDASM
	Next                                        ' Last byte is the received CRC value should
Return		                                    ' result in a CRC of 0.

@END

@MACRO_START OWCRC

@TARGET 14 Bit

OWCRC MACRO  P1, P2 
#IF (PRM_COUNT > 2) 
 #ERROR "OWCRC - Too many parameters" 
#ELSE 
 #IF (PRM_COUNT < 2) 
  #ERROR "OWCRC - Too few parameters" 
 #ELSE 
  #IF(PRM_1 != BYTE_ARRAY_PTR) 
   #ERROR "OWCRC - OW_DATA(Param1) Should be a BYTE array pointer" 
  #ENDIF 
  #IF(PRM_2 != Byte) && (PRM_2 != NUM8) && (PRM_2 != NUM16) && (PRM_2 != NUM32) 
   #ERROR "OWCRC - OW_LEN(Param2) Should be a Byte variable or number" 
  #ENDIF 
  #IF (PRM_1 == BYTE_ARRAY_PTR) 
 @  NUM_FSR P1 
  #ENDIF 
  #IF (PRM_2 == Byte) 
   BYTE_BYTE P2, OW_Len 
  #ENDIF 
  #IF (PRM_2 == NUM8) 
   NUM_BYTE P2, OW_Len 
  #ENDIF 
  #IF (PRM_2 == NUM16) 
   NUM_BYTE P2, OW_Len 
  #ENDIF 
  #IF (PRM_2 == NUM32) 
   NUM_BYTE P2, OW_Len 
  #ENDIF 
  GoSub Get_OW_Calc_C14 
 #ENDIF 
 #IF (OWCRC_RETURN != 1) 
  #ERROR "OWCRC - Mandatory return parameter misssing" 
 #ELSE 
  #IF(RETURN_TYPE !=Byte) && (RETURN_TYPE !=Word) && (RETURN_TYPE !=DWord) 
   #ERROR "OWCRC - Return variable should be a Byte variable or number" 
  #ELSE 
   #IF (RETURN_TYPE == Byte) 
    BYTE_BYTE OW_CRC_Calc, RETURN_VAR 
   #ENDIF 
  #ENDIF 
 #ENDIF 
#ENDIF 
ENDM 

@LOCAL
'Add Local (non-persistent) variables here
Dim OW_CRC_Calc As Byte
Dim OW_Len As Byte
Dim OW_Byte_Ptr As Byte
Dim OW_TmpDat As Byte
Dim OW_Idx As Byte
Dim OW_TestByte As Byte

@CODE

Get_OW_Calc_C14:
    OW_CRC_Calc = 0				            	 ' Set up initial CRC value
	For OW_Byte_Ptr = 0 To OW_Len -1   		 ' Run through all the data bytes
	   OW_TmpDat = INDF                    ' Get the next data byte
	   incf FSR
		 STATUS.0 = STATUS.7                 'if status.0 = 1 then status.7 = 1
ASM
				movlw 8
				movwf OW_Idx 											; Do this for all 8 bits of CRCByte
		OW_CRCLOOP
				movf OW_CRC_Calc,0 								; Put CRC into W
				xorwf OW_TmpDat,0 								; XOR CRC with CRCData
				movwf OW_TestByte 								; Put results in TestByte
				rrcf OW_TestByte,1 								; Shift TestByte.0 into Carry bit
				btfss STATUS,C 										; If Carry = 1, account for EXOR feedback gates
				GoTo OW_CRCSHIFT 									; Otherwise just shift CRC and CRCByte
				movf OW_CRC_Calc,0 								; Get latest copy of CRC
				xorlw 0x18 												; XOR with 18Hex
				movwf OW_CRC_Calc 								; Keep a copy of results
		OW_CRCSHIFT
				rrcf OW_CRC_Calc,1 								; Rotate CRC incorporating carry
				rrcf OW_TmpDat,1 									; Rotate CRCData, carry shifts in but not important
				decfsz OW_Idx,1 									; Keep track of #times through loop
				GoTo OW_CRCLOOP 									; back to start if not done all 8 bits
ENDASM
	Next                                    ' Last byte is the received CRC value should
Return

@END

@LIB_END