Datasheet

LP
Priority
HPD_A
0
1
0
1
0
1
HPD_B
0
1
HPD_OUT
0
1
Channel A
Z
0
1
ChannelB
0
1
HI-Z
DATA
LP
Priority
HPD_A
0
1
0
1
0
1
HPD_B
0
1
HPD_OUT
0
1
Channel A
Z
0
1
ChannelB
0
1
HI-Z
DATA HI-Z
DATA
SN75DP122A
SLLS939 – NOVEMBER 2008 ............................................................................................................................................................................................ www.ti.com
which the previously selected port with priority goes high again is covered in scenario 3.
Figure 41.
Figure 42.
3. One channel becomes active while other channel is already selected. There are also two possible starting
cases for this scenario:
– Case one: In this case the HPD input that is initially HIGH is from the port that has priority. Since the port
with priority is already selected, any activity on the HPD input from the other port does not have any
effect on the switch whatsoever (see Figure 43 ).
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