Freescale Semiconductor TWR-MCF52259-Ethenet - Manual (Page 128)

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Introduction to USB USB On-the-Go:
Negotiation process
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SRP (Session Request Protocol) Negotiations
OTG-B (device) asks OTG-A (host) for a USB OTG session by
signaling in one of two ways:
• Pulsing an analog data line (D+ or D-), and
• Pulsing V
BUS
through a relatively high impedance ( > 281 Ω Ω Ω Ω)
Note
:
The B-device pulses data line first and then
pulses V
BUS