我现在设计了两块板，一块是HDMI转FDPLINKIII用的是DS90UH949，别一块是FDPLINKIII转LVDS用的是DS90UH948，用I2C均可以通过读写寄存器的方式控制GPIO以及948的 HIGH-SPEED BACK CHANNEL的频率。但是现在用两对屏蔽差分线相连两个设备的时候949却无法识别948，自测试（BIST）也没法通过，请问一下是怎么回事呢，我应该怎么做呢。
下面是我用i2c-tools扫出来的两块板子的寄存器配置表：
./i2cdump 949
0 1 2 3 4 5 6 7 8 9 a b c d e f 0123456789abcdef
00: 1c 00 00 d2 80 00 00 00 00 00 00 00 00 20 00 00 ?..??........ ..
10: 00 00 00 88 00 01 fe 1e a1 a5 00 00 00 00 01 00 ...?.?????....?.
20: 00 00 25 00 00 00 00 00 00 20 20 90 00 00 a5 5a ..%...... ?..?Z
30: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
40: 00 00 00 00 80 00 00 00 00 00 00 00 00 00 00 01 ....?..........?
50: 94 a1 1e 00 a0 0c 00 00 00 00 02 20 02 06 44 00 ???.??....? ??D.
60: 22 02 00 00 10 00 00 00 00 00 00 00 00 00 00 00 "?..?...........
70: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
90: 43 8e 4e b5 8d 00 00 00 00 00 00 00 00 00 00 00 C?N??...........
a0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
b0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
c0: 00 00 a8 00 40 00 00 00 40 00 00 00 00 00 ff 00 ..?.@...@.......
d0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
e0: 00 00 a8 00 40 18 00 00 00 00 00 00 00 00 00 00 ..?.@?..........
f0: 5f 55 48 39 34 39 00 00 00 00 00 00 00 00 00 00 _UH949..........
I2C_DUMP_948
0 1 2 3 4 5 6 7 8 9 a b c d e f 0123456789abcdef
00: 58 04 00 f0 fe 1e 00 00 00 00 00 00 00 00 00 00 X?.???..........
10: 00 00 00 00 00 00 00 00 00 01 00 00 22 10 00 00 .........?.."?..
20: 00 00 00 20 08 00 83 84 20 00 00 00 00 00 00 00 ... ?.?? .......
30: 00 00 90 25 01 00 00 88 00 00 00 00 20 40 23 00 ..?%?..?.... @#.
40: 43 03 03 00 60 88 00 00 0f 00 00 08 00 00 63 00 C??.`?..?..?..c.
50: 03 10 00 01 80 00 00 00 00 7f 20 20 00 00 00 00 ??.??....? ....
60: 00 00 00 00 10 00 00 00 00 00 00 00 00 00 00 00 ....?...........
70: 00 00 00 07 07 08 00 00 00 00 00 00 02 00 00 00 ...???......?...
80: 23 9e 5e 21 e3 00 00 00 00 00 00 00 00 00 00 00 #?^!?...........
90: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
a0: 00 00 7d 00 00 00 00 00 00 00 00 00 00 00 00 00 ..}.............
b0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
c0: 00 00 00 00 00 00 00 00 c0 00 00 00 00 00 00 00 ........?.......
d0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
e0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
f0: 5f 55 48 39 34 38 00 00 00 00 00 00 00 00 00 00 _UH948..........
