Datasheet

821
SAM9G45 [DATASHEET]
Atmel-6438O-ATARM-SAM9G45-Datasheet_08-Dec-15
36. USB High Speed Host Port (UHPHS)
36.1 Description
The USB High Speed Host Port (UHPHS) interfaces the USB with the host application. It handles Open HCI
protocol (Open Host Controller Interface) as well as Enhanced HCI protocol (Enhanced Host Controller Interface).
36.2 Embedded Characteristics
The SAM9G45 features USB communication ports as follows:
 2 Ports USB Host full speed OHCI and High speed EHCI
 1 Device High speed
USB Host Port A is directly connected to the first UTMI transceiver.
The Host Port B is multiplexed with the USB device High speed and connected to the second UTMI port. The
selection between Host Port B and USB device high speed is controlled by a the UDPHS enable bit located in the
UDPHS_CTRL register.
Figure 36-1. USB Selection
 Compliant with Enhanced HCI Rev 1.0 Specification
 Compliant with USB V2.0 High-speed and Full-speed Specification
 Supports Both High-speed 480 Mbps and Full-speed 12 Mbps USB devices
 Compliant with Open HCI Rev 1.0 Specification
 Compliant with USB V2.0 Full-speed and Low-speed Specification
 Supports Both Low-speed 1.5 Mbps and Full-speed 12 Mbps USB devices
 Root Hub Integrated with 2 Downstream USB Ports
 Shared Embedded USB Transceivers
36.2.1 EHCI
The USB Host Port controller is fully compliant with the Enhanced HCI specification. The USB Host Port User
Interface (registers description) can be found in the Enhanced HCI Rev 1.0 Specification available on
www.intel.com. The standard EHCI USB stack driver can be easily ported to Atmel’s architecture in the same way
all existing class drivers run, without hardware specialization.
36.2.2 OHCI
The USB Host Port integrates a root hub and transceivers on downstream ports. It provides several Full-speed
half-duplex serial communication ports at a baud rate of 12 Mbit/s. Up to 127 USB devices (printer, camera,
mouse, keyboard, disk, etc.) and the USB hub can be connected to the USB host in the USB “tiered star” topology.
HS
Transceiver
DMA
HS
USB
DMA
HS EHCI
FS OHCI
PA P B
HS
Transceiver
1
0
EN_UDPHS