mirror16:
;r6 = bit reversed r7, r7 = bit reversed r6
;17 clocks + ret
;Initial state:	r6 =	 hgfedcba
;		r7 =	 HGFEDCBA
;		CY  =	 	  y
 
	rol	r6	;gfedcbay h
	ror	r7	;hHGFEDCB A
	rol	r6	;fedcbayA g
	ror	r7	;ghHGFEDC B
	rol	r6	;edcbayAB f
	ror	r7	;fghHGFED C
	rol	r6	;dcbayABC e
	ror	r7	;efghHGFE D
	rol	r6	;cbayABCD d
	ror	r7	;defghHGF E
	rol	r6	;bayABCDE c
	ror	r7	;cdefghHG F
	rol	r6	;ayABCDEF b
	ror	r7	;bcdefghH G
	rol	r6	;yABCDEFG a
	ror	r7	;abcdefgh H
	rol	r6	;ABCDEFGH y
 
	ret