RM0082
HS_USB2.0 host
Doc ID 018672 Rev 1
411/844
22 HS_USB2.0
host
22.1 Overview
Within its High-Speed (HS) Connection Subsystem, the device provides one USB 2.0 Host
with 2 physical ports which are fully compliant with the Universal Serial Bus specification
(version 2.0), and offering an interface to the industry-standard AHB bus.
Main features provided by USB 2.0 Host are listed below:
●
A PHY interface implementing a USB 2.0 Transceiver Macro-cell Interface plus
(UTMI+) fully compliant with UTMI+ specification (revision 1.0), to execute serialization
and de-serialization of transmissions over the USB line;
●
Either 30 MHz clock for 16 bit interface or 60 MHz for 8 bit interface are supported by
the UTMI+ PHY interface;
●
A USB 2.0 Host Controller (UHC) which is connected to the AHB bus and generates
the commands for the UTMI+ PHY;
●
The UHC complies with both the Enhanced Host Controller Interface (EHCI)
specification (version 1.0) and the Open Host Controller Interface (OHCI) specification
(version 1.0a);
●
The UHC supports the 480 Mbps high-speed (HS) for USB 2.0 through an embedded
EHCI Host Controller, as well as the 12 Mbps full-speed (FS) and the low-speed (LS)
for USB 1.1 through two integrated OHCI Host Controller;
●
All clock synchronization is handled within the UHC;
●
An AHB slave for each controller (1 EHCI and 2 OHCI), acting as programming
interface to access to control and status registers;
●
An AHB master for each controller (1 EHCI and 2 OHCI) for data transfer to system
memory, supporting 8, 16, and 32 bit wide data transactions on the AHB bus;
●
32 bit AHB bus addressing.
Only one port can be selected to be used for 480 Mbps (HS) communication by the EHCI
controller. When one port is used by the EHCI, the other can only be used for full-speed
(FS) or low-speed (LS) communication (by the OHCI controller).