RM0082
HS_USB2.0 host
Doc ID 018672 Rev 1
413/844
Major blocks of the EHCI Host Controller are described in
Section 22.4: EHCI host controller
22.3.3 OHCI
host
controller
Two OHCI Host Controllers compliant with the OHCI specification (version 1.0a) are also
integrated in the UHC to support the 12 Mbps full-speed (FS) and the 1.5 Mbps low-speed
(LS) operation of USB 1.1. FS/LS device connected to port0 is managed by OHCI0 and
port1 is managed by OHCI1.
Major blocks of the OHCI Host Controller are described in
22.4
EHCI host controller blocks
22.4.1 List
processor
The List Processor is the main block of the EHCI Host Controller. The List Processor is
implemented with multiple state machines to perform the list service flow, which is set up by
the Host Controller Driver (HCD) according to the priority set in the Operational registers
Section 22.4.2: Operational registers
In addition, the List Processor consists of a controller that interfaces with all the other EHCI
Host Controller blocks, such as the AHB BIU (Master module), the Packet Buffer, the EHCI
Operational registers, the SOF Generators and the Root Hub.
22.4.2 Operational
registers
This block exposes the implemented EHCI Capability and Operational registers as defined
in the USB EHCI specification. In addition, certain IP-specific extended registers are also
implemented, in order to configure features like Packet Buffer depth, break memory transfer,
frame length.
The Operational registers block interfaces with the AHB BIU (Slave module), the List
Processor and the Root Hub.
22.4.3
Start-Of-Frame (SOF) generator
The SOF Generator block implements the counter which generates the Start-Of-Frame
(SOF) packets to supply micro-SOFs for each microframe. The SOF counter runs in the
PHY clock domain.
Microframe duration is derived from the EHCI Frame Length Adjustment (FLADJ) register
value. This ensures that the Host microframe duration and per-port microframe duration
remain the same.
This block interfaces with the List Processor only.
22.4.4 Packet
buffer
The Packet Buffer (PBUF) block provides storage and control for IN/OUT data transaction,
with a configured size of 1024 bytes (256 x 32 = 1024 bytes).