
Device Protocol
In device mode, the MAC performs the following functions:
• Handles USB reset sequence
• Handles speed enumeration
• Detects USB suspend and resume activity on the USB link
• Initiates remote wakeup
• Decodes SOF packets
OTG Protocol
The MAC handles HNP and SRP for OTG operation. HNP provides a mechanism for swapping host and
device roles. SRP provides mechanisms for the host to turn off V
BUS
to save power, and for a device to request
a new USB session.
LPM Functions
The USB OTG controller supports LPM in both host and device modes. With this feature, the USB OTG
controller can enter a sleep state when a successful LPM transaction occurs on the USB link.
Wakeup and Power Control
To reduce power, the USB OTG controller supports a power-down mode. In power-down mode, the controller
and the PHY can shut down their clocks. The controller supports wakeup on the detection of the following
events:
• Resume
• Remote wakeup
• Session request protocol
• New session start
PHY Interface Unit
The USB OTG controller supports synchronous SDR data transmission to a ULPI PHY. The SDR mode
implements an eight-bit data bus.
ULPI PHY Interface
Table 18-2: ULPI PHY Interfaces
The ULPI PHY interface is synchronous to the
ulpi_clk
signal coming from the PHY.
Description
Direction
Bit Width
Port Name
ULPI Clock
Receives the 60-MHz clock supplied by the high-speed
ULPI PHY. All signals are synchronous to the positive
edge of the clock.
Input
1
ulpi_clk
USB 2.0 OTG Controller
Altera Corporation
cv_54018
Device Protocol
18-8
2013.12.30