ASCII HEX Decimal to 32bit via input routine by http://elm-chan.org
;-----------------------------------------------------------------------------; ; Get value of hexdecimal string (32 bit) ; ; Register Variables: ; ; Call: X -> Hexdecimal strings (space separated and EOL terminated) ; var3:0 = <Don't care> ; tmp1:0 = <Don't care> (high register must be assigned) ; ; Result: ne,cc: Successful ; var3:0 = 32 bit result ; X -> Separater character ; eq,cc: No data (reached EOL) ; var3:0 = 0 ; X -> EOL ; eq,cs: Invalid character is detected ; var3:0 = <Unknown> ; X -> Error character ; ; Size: 44 words ; Clock: depends on the string ; Stack: 0 byte get_valh: clr var0 ;var = 0; clr var1 ; clr var2 ; clr var3 ;/ ld tmp0, X ;Skip " " cpi tmp0, ' ' ; brcc PC+4 ; clc ;no data ; sez ; ; ret ;/ ; brne PC+3 ; adiw XL, 1 ; rjmp PC-8 ;/ ;--- processing loop cpi tmp0, ' '+1 ;convert a hexchar into its value brcc PC+4 ; clz ;successful ; clc ; ; ret ;/ ; cpi tmp0, 'a' ; brcs PC+2 ; subi tmp0, 0x20 ; subi tmp0, '0' ; brcc PC+4 ; sec ;error ; sez ; ; ret ;/ ; cpi tmp0, 10 ; brcs PC+6 ; subi tmp0, 7 ; cpi tmp0, 10 ; brcs PC-7 ; cpi tmp0, 16 ; brcc PC-9 ;/ ldi tmp1, 4 ;var = var << 4 + tmp0; lsl var0 ; rol var1 ; rol var2 ; rol var3 ; dec tmp1 ; brne PC-5 ; or var0, tmp0 ;/ adiw XL, 1 ;Next character ld tmp0, X ; rjmp PC-30 ;/