[Oberon] Bit manipulation in Oberon-07

[Aubrey McIntosh]

If they are manipulating a hardware register that is based on bits, why is
the data ever in the form of an integer?

On Wed, Oct 24, 2018 at 12:16 PM Tomas Kral <thomas.kral at email.cz> wrote:

> On Wed, 24 Oct 2018 14:47:30 +0200
> Tomas Kral <thomas.kral at email.cz> wrote:
>
> > but how to access the
> > individual bits?
>
> How about this, if not correct or too silly?
>
> MODULE Bits; (*TK 24.10.2018 Word Byte Bit SET masks example*)
>   IMPORT S := SYSTEM, O := Out;
>
> CONST
>   m0 = {0}; m1 = {1}; m2 = {2}; m3 = {3}; m4 = {4}; m5 = {5}; m6 = {6}; m7
> = {7}; (*bit masks*)
>   m0123 = {3,2,1,0}; (*lower nibble*) m4567 = {4,5,6,7}; (*upper nibble*)
>   m16 = {0..15}; (*lower short*) m24 = {16..31}; (*upper short*)
>   m31 = {0..31}; (*word*)
>
> VAR
>   wd: INTEGER;
>   b0,b1,b2,b3: BYTE; (*b0: LSB, b3: MSB*)
>   bit0, bit1, bit2, bit3, bit4,  bit5, bit6, bit7: BYTE; (*bits' values*)
>   s: SET;
>
>   PROCEDURE Show*;
>   BEGIN
>     wd := 0F3F2F1F0H;
>     b0 := wd MOD 100H; O.Hex(b0); O.Ln; (*one cycle or more?*)
>     b1 := wd DIV 100H MOD 100H; O.Hex(b1); O.Ln;
>     b2 := wd DIV 10000H MOD 100H; O.Hex(b2); O.Ln;
>     b3 := wd DIV 1000000H MOD 100H; O.Hex(b3); O.Ln; O.Ln;
>     bit0 := ORD(ODD(b0)); O.Hex(bit0); O.Ln;
>     bit1 := b1 MOD 2; O.Hex(bit1); O.Ln;
>     bit2 := b2 DIV 2 MOD 2; O.Hex(bit2); O.Ln;
>     bit3 := b3 DIV 4 MOD 2; O.Hex(bit3); O.Ln;
>     (*s := S.VAL(SET, wd) * m4);*) (*using mask {4}*)
>     bit4 := b3 DIV 8 MOD 2; O.Hex(bit4); O.Ln;
>     bit5 := b3 DIV 16 MOD 2; O.Hex(bit5); O.Ln;
>     bit6 := b3 DIV 32 MOD 2; O.Hex(bit6); O.Ln;
>     bit7 := b0 DIV 64 MOD 2; O.Hex(bit7); O.Ln; O.Ln;
>     IF bit0 > 0 THEN INCL(s, bit0) END ;
>     IF bit1 > 0 THEN INCL(s, bit1*2) END ;
>     IF bit2 > 0 THEN INCL(s, bit2*4) END ;
>     IF bit3 > 0 THEN INCL(s, bit3*8) END ;
>     IF bit4 > 0 THEN INCL(s, bit4*16) END ;
>     IF bit5 > 0 THEN INCL(s, bit5*32) END ;
>     IF bit6 > 0 THEN INCL(s, bit6*64) END ;
>     IF bit7 > 0 THEN INCL(s, bit7*128) END ;
>     (*s := S.VAL(SET, wd) * (m0+m1+m2+m3);*) (*using mask {0..3}*)
>     O.Hex(ORD(s)); O.Ln
>   END Show;
>
> BEGIN
> END Bits.Show
>
>
> --
> Tomas Kral <thomas.kral at email.cz>
> --
> Oberon at lists.inf.ethz.ch mailing list for ETH Oberon and related systems
> https://lists.inf.ethz.ch/mailman/listinfo/oberon
>


-- 
Aubrey McIntosh, Ph.D.
1502 Devon Circle
Austin TX 78723
(512) 791-3801
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