Intel
®
IXP45X and Intel
®
IXP46X Product Line of Network Processors—USB 2.0 Host Controller
Intel
®
IXP45X and Intel
®
IXP46X Product Line of Network Processors
Developer’s Manual
August 2006
364
Order Number: 306262-004US
9.8
Detailed Register Descriptions
The MMR registers for the USB Host are (for the most part) EHCI specification
compliant, with exceptions as noted. The USB Host supports byte access to the MMR
space and the default access is “little-endian” after power-up or hardware reset. The
endian support for the MMR space is programmable which enables “big-endian” access.
This is important for byte access support and it is expected that one of the very first
operations being performed on the USB host is to correctly set the required endian
mode. Please see the USBMODE register description for details.
VUSB_HS_BANDWIDTH_TESTING
Controls the testing of the core. This constant should
always be zero.
0=Normal Bandwidth Testing
1=Bandwidth Starved
Testing (subset of Normal
Bandwidth Testing) Used for
system clock less than
30 MHz.
VUSB_HS_DEV_EP
Controls the maximum number of endpoints
supported by the core.
Integer values between 2
and 16. Set this to 1 for
single and multi-port host-
only products.
VUSB_HS_NUM_PORT
Controls the number of downstream ports in a host
implementation.
Integer values between 1
and 8. Set this to 1 for non-
multi-port products.
VUSB_HS_TT_PERIODIC_CONTEXTS
USB 2.0 specification requires a hub Transaction
Translator to have 16 periodic contexts. However, for
some host applications 4 may be adequate and a gate
count savings can be realized.
4 or 16.
VUSB_HS_RX_DEPTH
Controls the size of the receive latency buffer.
Powers of 2 from 8 to 2048.
VUSB_HS_RX_BURST
Controls the Bus burst size for Rx DMA data transfers. Integer values from 4 to
128.
VUSB_HS_TX_CHAN
Controls the size of each of the transmit latency
buffers.
Powers of 2 from 16 to 128.
VUSB_HS_TX_BURST
Controls the Bus burst size for Tx DMA data transfers. Integer values from 4 to
128.
VUSB_HS_TX_LOCAL_
CONTEXT_REGISTERS
Determines if device transmit context registers are
implemented as a register file or stored in the TX-
FIFO.
1=Implement device
transmit contexts in
registers. (Removes need for
read port A on TX-FIFO)
0=Store device transmit
contexts in TX FIFO.
(Smaller total gate count but
uses 4 words of
VUSB_HS_TX_CHAN per
endpoint)
VUSB_HS_HCIVERSION
Software readable host silicon version.
Unsigned 16-bit integer.
VUSB_HS_DCIVERSION
Software readable device silicon version.
Unsigned 16-bit integer.
Table 121.
Configuration Controls (Sheet 2 of 2)
Constant
Description
Supported Values
Table 122.
Register Legend
Attribute
Legend
Attribute
Legend
RV
Reserved
RC
Read Clear
PR
Preserved
RO
Read Only