Western Digital T13/2132-D - Manual (Page 23)

June 23, 2010 T13/2132-D Revision 3
Working Draft Enhanced Disk Drive - 4 (EDD-4) 11
Each pair of bytes in an ATA string is swapped as shown in table 4.
If the field contains the string “abcdefg ”, including one padding space character at the end, then the word and
byte representations for the field are shown in table 5.
Table 4 — ATA string byte swapping
Word Byte Character in string
0 0 Second character
1 First character
1 2 Fourth character
3 Third character
... ... ...
n 2n Last character
2n+1 Second-to-last character
Table 5 — ATA firmware revision example
Word Value Byte Value
23 6162h (i.e., “ba”) 36 62h (i.e., ‘b’)
37 61h (i.e., ‘a’)
24 6364h (i.e., “dc”) 38 64h (i.e., ‘d’)
39 63h (i.e., ‘c’)
25 6566h (i.e., “fe”) 40 66h (i.e., ‘f’)
41 65h (i.e., ‘e’)
26 6720h (i.e., “ g”) 42 20h (i.e., ‘ ’, the space character)
43 67h (i.e., ‘g’)