Atmel AVR Microcontroller Radix Conversions

16bit to ASCII Decimal signed via output routine by http://elm-chan.org

;-----------------------------------------------------------------------------;
; Universal decimal string conversion (8/16/32 bit signed)
;
; Register Variables:
; Call: var3:0 = 32 bit value to be displayed
; len = String length
; tmp1:0 = <Don't care> (high register must be assigned)
; tmp2 = <Don't care>
;
; Result:var3:0 = <Unknown>
; len = <Not changed>
; tmp1:0 = <Unknown>
; tmp2 = 0
;
; Size: 58 words
; Clock: depends on output routine
; Stack: 11 bytes max (+output routine)
;
; Examples: var len output
; 100 0 "100"
; -1234 0 "-1234"
; 31450000 0 "31450000"
; 0 7 " 0"
; -400 5 " -400"
; 100 5 " 100"
; 100 2 "100"
mk_dec8: clr var1 ;8 bit entry
 sbrc var0,7 ;
 dec var1 ;/
mk_dec16: clr var2 ;16 bit entry 
 sbrc var1,7 ;
 dec var2 ;/
mk_dec24: clr var3 ;24 bit entry
 sbrc var2,7 ;
 dec var3 ;/
mk_dec32: ;32 bit entry
 clr tmp2 ;digit counter
 clt ;Remove sign
 tst var3 ;
 brpl PC+10 ;
 set ;
 com var0 ;
 com var1 ;
 com var2 ;
 com var3 ;
 adc var0,tmp2 ;
 adc var1,tmp2 ;
 adc var2,tmp2 ;
 adc var3,tmp2 ;/
 inc tmp2 ;---- decimal string generating loop
 clr tmp0 ;var1 /= 10;
 ldi tmp1,32 ;
 lsl var0 ;
 rol var1 ;
 rol var2 ;
 rol var3 ;
 rol tmp0 ;
 cpi tmp0,10 ;
 brcs PC+3 ;
 subi tmp0,10 ;
 inc var0 ;
 dec tmp1 ;
 brne PC-10 ;/
 subi tmp0,-'0' ;Push the remander (a decimal digit)
 push tmp0 ;/
 cp var0,tmp1 ;if(var =! 0)
 cpc var1,tmp1 ; continue digit loop;
 cpc var2,tmp1 ;
 cpc var3,tmp1 ;
 brne PC-20 ;/
 brtc PC+4 ;Put sign
 ldi var0,'-' ;
 push var0 ;
 inc tmp2 ;/
 cp tmp2,len ;Adjust string length (this can be removed for auto-length)
 brcc PC+5 ;
 inc tmp2 ;
 ldi var0,' ' ;
 push var0 ;
 rjmp PC-5 ;/
 pop var0 ;Put decimal string
 rcall xmit ;<-- Put a char (var0) to memory, console or any display device
 dec tmp2 ;
 brne PC-3 ;/
 ret

.