RT1731
Transmitting or Receiving BMC Encoded Frame Terminated
The end of a BMC encoded Frame with an encoded zero for which the final bit of the Frame is terminated by a high
to low transition.
Preamble for
next frame
Final bit
of frame
0
Trailing edge
of final bit
0
High Impedance
(level set by Rp/Rd)
1UI
min t
HoldLowBMC
max t
EndDriveBMC
t
InterFrameGap
Figure 3. tInterFrameGap
Biphase Mark Coding (BMC) Signaling Scheme
Biphase Mark Coding is the physical layer Signaling Scheme for carrying USB Power Delivery Messages. This
encoding assumes a dedicated DC connection, identified as the CC wire, which is used for sending PD Messages.
Preamble
Sync-1
Sync-1
0
1
0
1
0
1
0
1
0
0
0
1
1
0
0
0
1
1
Data In
BMC
Figure 4. BMC Example
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DS1731-01 April 2019
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5
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