Functional Description of the USB OTG Controller
USB OTG Controller Block Description
Figure 18-2: USB OTG Controller Block Description
Details about each of the units that comprise the USB OTG controller are shown below.
SPRAM
External USB Transceiver
L3 Interconnect
ULPI PHY Interface
Slave Interface
Master Interface
Application Interface Unit
Packet FIFO Controller
Media Access Controller
Wakeup and PHY Controller
PHY Interface
USB OTG
Controller
Master Interface
The master interface includes a built-in DMA controller. The DMA controller moves data between external
memory and the media access controller (MAC).
Properties of the master interface are controlled through the USB L3 Master HPROT Register (
l3master
)
in the system manager. These bits provide access information to the L3 interconnect, including whether or
not transactions are cacheable, bufferable, or privileged.
Bits in the
l3master
register can be updated only when the master interface is guaranteed to be
in an inactive state.
Note:
Slave Interface
The slave interface allows other masters in the system to access the USB OTG controller’s CSRs. For testing
purposes, other masters can also access the SPRAM.
Slave Interface CSR Unit
The slave interface can read from and write to all the CSRs in the USB OTG controllers. All register accesses
are 32 bits.
Altera Corporation
USB 2.0 OTG Controller
18-5
Functional Description of the USB OTG Controller
cv_54018
2013.12.30