On the off chance that you may want to know more about these signals: The Association for Electric Home Appliances is a Japanese organization called Kaseikyo in Japan.  They have defined an IR protocol (termed Kaseikyo, generally) which is sometimes used by Panasonic, Denon, Fujitsu, Mitsubishi, Teac, Sharp, etc.  This particular version of the Kaseikyo protocol is also known as SharpDVD (because it was first seen in Sharp DVD players)

Each byte in 0x555AF468808A should be read with the bits reversed.  The basic structure is:

55    01010101 -> 10101010 = 0xAA = 170 Sharp OEM designator
5A    01011010 -> 10100101 = 0x5A =   90 Sharp OEM designator
F       Always 0xF in SharpDVD
4       0100 -> 0010 = 0x2  = 2     Device number
68     01101000 -> 00010110 = 0x16 = 22    Subdevice number
80     10000000 -> 00000001 = 0x1 = 1      Function number
8       Always 0x8 in SharpDVD
A       Check sum  (XOR of previous 5 nibbles).
So you can generate the Pronto Hex with e.g. IrScutinizer by selecting SharpDVD, and entering 2 in the D box, 22 (or0x16) in the S box, and 1 in the F box.  Other functions can be generated by reversing the bits in the second to last byte, and entering the result into the F box.