HS_USB2.0 host
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22.2 Block
diagram
Figure 36.
UHC block diagram.
22.3
Main functions description
22.3.1
AHB bus interface unit (BIU)
USB 2.0 Host access to the AHB bus is granted by the AHB Bus Interface Unit (BIU), which
consists of a Master module and a Slave module.
The AHB BIU Slave module acts a slave on the AHB and responds to all EHCI/OHCI
Operational registers (
Section 22.4.2: Operational registers
) accesses from an AHB master.
In particular, this module allows RW access to its operational registers through the AHB bus.
Note:
There is only a single AHB slave port in AHB BIU Slave module for both EHCI and OHCI
host controller registers access.
The AHB BIU Master module, acting as a master on the AHB, receives requests from the
List Processor block
Section 22.4.1: List processor
within the EHCI Host Controller, and
transfers data with system memory through the AHB bus. The AHB BIU Master supports 8-,
16-, and 32 bit data transfers, and 32 bit address transfers.
22.3.2 EHCI
host
controller
An EHCI Host Controller compliant with the EHCI specification (version 1.0) is embedded
within the UHC to support the 480 Mbps high-speed (HS) transaction of USB 2.0.HS device
connected to one of the two downstream ports.
A
M
BA
AH
B
AHB
BI
U
EHCI
OHCI
OHCI
SOF
Generator
EHCI
Operation
List
Processor
Packet Buffer
Root
Hu
b
Port0
Port1
UTMI+P
H
Y
To Ext
e
rn
al PAD
USB2.0 EHCI Controller
USB1.1 OHCI
Controller
USB1.1 OHCI
Controller
UHC