>Harry wrote:

   >> Does anybody have a routine for implementing bit reversal ? > i.e.
   11000000 to be converted to 00000011


   >This topic has just been discussed in the PIC16CXX forum on the
   >Microchip BBS (see messages 127246,127625 and 127775).  Here is the
   >solution given by Mark Palmer of Microchip:

   >CLRF     REVERSE         ; Precondition Register to 0
   >BTFSC   NORMAL, 7        ; MSb set?
   >BSF       REVERSE, 0     ; Set LSb
   ... etc...


   here's another solution, but I'm no pic expert, so I don't know if this
   would be faster and/or shorter than the above solution...

                                                     // ad_value: abcd efgh
      ad_value=((ad_value<<4)&0xf0)|((ad_value>>4)&0x0f);     //  efgh abcd
      ad_value=((ad_value<<2)&0xcc)|((ad_value>>2)&0x33);     //  ghef cdab
      ad_value=((ad_value<<1)&0xaa)|((ad_value>>1)&0x55);     //  hgfe dcba



John Maushammer
jmaushammer@SMTPLINK.CTA.COM