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Intel
®
IXP45X and Intel
®
IXP46X Product Line of Network Processors
August 2006
Developer’s Manual
Order Number: 306262--, Revision: 004US
341
USB 1.1 Device Controller—Intel
®
IXP45X and Intel
®
IXP46X Product Line of Network
Processors
8.5.29
UDC Byte Count Register 14
(UBCR14)
The Byte-Count Register maintains the remaining byte count in the active buffer of out
Endpoint 14.
8.5.29.1
Endpoint 14 Byte Count (BC[7:0])
The byte count is updated after each byte is read. When software receives an interrupt
that indicates the endpoint has data, it can read the byte count register to determine
the number of bytes that remain to be read.
The number of bytes that remain in the input buffer is equal to the byte count +1.
8.5.30
UDC Endpoint 0 Data Register
(UDDR0)
The UDC Endpoint 0 Data Register is an 16-entry by 8-bit bidirectional FIFO. When the
host transmits data to the UDC Endpoint 0, the Intel XScale processor reads the UDC
Endpoint 0 Register to access the data.
When the UDC sends data to the host, the Intel XScale processor writes the data to be
sent in the UDC Endpoint 0 Register. The Intel XScale processor can only read and write
the FIFO at specific points in a control sequence.
Register
UBCR12
Bits
Name
Description
31:8
(Reserved)
7:0
BC
Byte Count (read-only).
Number of bytes in the FIFO is Byte Count plus 1 (BC+1).
Register Name:
UBCR14
Hex Offset Address:
0 x C800B07C
Reset Hex Value:
0x00000000
Register
Description:
Universal Serial Bus Device Endpoint 14 Byte Count
Access: Read-Only
Bits
31
8
7
0
(Reserved)
BC[7:0]
X
0
0
0
0
0
0
0
0
Resets (Above)
Register
UBCR14
Bits
Name
Description
31:8
(Reserved)
7:0
BC
Byte Count (read-only).
Number of bytes in the FIFO is Byte Count plus 1 (BC+1).