; Bin2ToAsc5
; ==========
; converts a 16-bit-binary to a 5 digit ASCII-coded decimal
; In: 16-bit-binary in rBin1H:L, Z points to the highest
;   of 5 ASCII digits, where the result goes to
; Out: Z points to the beginning of the ASCII string, lea-
;   ding zeros are filled with blanks
; Used registers: rBin1H:L (content is not changed),
;   rBin2H:L (content is changed), A
; Called subroutines: Bin2ToBcd5
;
;.CSEG
;.include "../includes/tn45def.inc"
.def	rBin1L		= r5	;
.def	rBin1H		= r6	;
.def	rBin2L		= r7	;
.def	rBin2H		= r8	;
;.def	A		= r16	;

Bin2ToAsc5:
	rcall Bin2ToBcd5 ; convert binary to BCD
	ldi A,4 ; Counter is 4 leading digits
	mov rBin2L,A
Bin2ToAsc5a:
	ld A,z ; read a BCD digit
	tst A ; check if leading zero
	brne Bin2ToAsc5b ; No, found digit >0
	ldi A,' ' ; overwrite with blank
	st z+,A ; store and set to next position
	dec rBin2L ; decrement counter
	brne Bin2ToAsc5a ; further leading blanks
	ld A,z ; Read the last BCD
Bin2ToAsc5b:
	inc rBin2L ; one more char
Bin2ToAsc5c:
	subi A,-'0' ; Add ASCII-0
	st z+,A ; store and inc pointer
	ld A,z ; read next char
	dec rBin2L ; more chars?
	brne Bin2ToAsc5c ; yes, go on
	;ldi	 A,0xFF
	;st 	Z+,A ; store 0xFF and inc pointer
	;sbiw ZL,5 ; Pointer to beginning of the BCD
	ret ; done

; =========
Bin2ToAsc5_:
	rcall Bin2ToBcd5 ; convert binary to BCD
	ldi A,4 ; Counter is 4 leading digits
	mov rBin2L,A
Bin2ToAsc5a_:
	ld A,z ; read a BCD digit
	tst A ; check if leading zero
	brne Bin2ToAsc5b_ ; No, found digit >0
	ldi A,' ' ; overwrite with blank
	st z+,A ; store and set to next position
	dec rBin2L ; decrement counter
	brne Bin2ToAsc5a_ ; further leading blanks
	ld A,z ; Read the last BCD
Bin2ToAsc5b_:
	inc rBin2L ; one more char
Bin2ToAsc5c_:
	subi A,-'0' ; Add ASCII-0
	st z+,A ; store and inc pointer
	ld A,z ; read next char
	dec rBin2L ; more chars?
	brne Bin2ToAsc5c_ ; yes, go on
	;ldi	 A,0xFF
	;st 	Z+,A ; store 0xFF and inc pointer
	;sbiw ZL,5 ; Pointer to beginning of the BCD
	ret ; done	
	
; Bin2ToBcd5
; ==========
; converts a 16-bit-binary to a 5-digit-BCD
; In: 16-bit-binary in rBin1H:L, Z points to first digit
;   where the result goes to
; Out: 5-digit-BCD, Z points to first BCD-digit
; Used registers: rBin1H:L (unchanged), rBin2H:L (changed),
;   A
; Called subroutines: Bin2ToDigit
;
Bin2ToBcd5:
	push rBin1H ; Save number
	push rBin1L
	ldi A, HIGH(10000) ; Start with tenthousands
	mov rBin2H,A
	ldi A, LOW(10000)
	mov rBin2L,A
	rcall Bin2ToDigit ; Calculate digit
	ldi A, HIGH(1000) ; Next with thousands
	mov rBin2H,A
	ldi A, LOW(1000)
	mov rBin2L,A
	rcall Bin2ToDigit ; Calculate digit
	ldi A, HIGH(100) ; Next with hundreds
	mov rBin2H,A
	ldi A, LOW(100)
	mov rBin2L,A
	rcall Bin2ToDigit ; Calculate digit
	ldi A, HIGH(10) ; Next with tens
	mov rBin2H,A
	ldi A, LOW(10)
	mov rBin2L,A
	rcall Bin2ToDigit ; Calculate digit
	st z,rBin1L ; Remainder are ones
	sbiw ZL,4 ; Put pointer to first BCD
	pop rBin1L ; Restore original binary
	pop rBin1H
	ret ; and return
;
; Bin2ToDigit
; ===========
; converts one decimal digit by continued subraction of a
;   binary coded decimal
; Used by: Bin2ToBcd5, Bin2ToAsc5, Bin2ToAsc
; In: 16-bit-binary in rBin1H:rBin2L, binary coded decimal in
;   rBin2H:rBin2L, Z points to current BCD digit
; Out: Result in Z, Z incremented
; Used registers: rBin1H:rBin2L (holds remainder of the binary),
;   rBin2H:rBin2L (unchanged), A
; Called subroutines: -
;
Bin2ToDigit:
	clr A ; digit count is zero
Bin2ToDigita:
	cp rBin1H,rBin2H ; Number bigger than decimal?
	brcs Bin2ToDigitc ; MSB smaller than decimal
	brne Bin2ToDigitb ; MSB bigger than decimal
	cp rBin1L,rBin2L ; LSB bigger or equal decimal
	brcs Bin2ToDigitc ; LSB smaller than decimal
Bin2ToDigitb:
	sub rBin1L,rBin2L ; Subtract LSB decimal
	sbc rBin1H,rBin2H ; Subtract MSB decimal
	inc A ; Increment digit count
	rjmp Bin2ToDigita ; Next loop
Bin2ToDigitc:
	st z+,A ; Save digit and increment
	ret ; done
	
; Asc2DCB
;Converts Two ASCII-coded by DCB
;In: 16-bit-binary in rBin1H:rBin2L ASCII. For example: 37:30
;Out: Result A=70
	ldi	A,0xF0
	swap rBin1H
	and rBin1H,A
	SWAP A
	and rBin1L,A
	mov	A,rBin1L
	and A,rBin1H
	ret