SLLSE09J November 2009 – July 2021 TUSB1210
PRODUCTION DATA
The HS transmitter is always operated via the ULPI parallel interface. The parallel data on the interface is serialized, bit stuffed, NRZI encoded, and transmitted as a dc output current on DP or DM depending on the data. Each line has an effective 22.5 Ω load to ground, which generates the voltage levels for signaling.
A disconnect detector is also part of the HS transmitter. A disconnect on the far end of the cable causes the impedance seen by the transmitter to double thereby doubling the differential amplitude seen on the DP/DM lines of Section 6.13.