L-USS820D-DB LSI, L-USS820D-DB Datasheet - Page 25

• Manufacturer Part Number: L-USS820D-DB
• Manufacturer: LSI

Specifications of L-USS820D-DB

• Operating Temperature (min): -20C
• Operating Temperature Classification: Commercial
• Operating Temperature (max): 85C
• Rad Hardened: No
• Lead Free Status / RoHS Status: Compliant

Data Sheet, Rev. 7
September 2004
Agere Systems Inc.
Register Interface
Table 21. Function Address Register (FADDR)—Address: 10H; Default: 0000 0000B
This SFR holds the address for the USB function. During bus enumeration, it is written by firmware with a unique
value assigned by the host. If MCSR.FEAT = 1, this register is reset to 0 if a USB RESET is detected.
Table 22. Transmit FIFO Data Register (TXDAT)—Address: 00H; Default: 0000 0000B
Data to be transmitted by the FIFO specified by EPINDEX is first written to this register. This register is endpoint
indexed. TXDAT must not be written if TXFIF = 11.
Table 23. Transmit FIFO Byte-Count High and Low Registers (TXCNTH, TXCNTL)—Address:
Written by firmware to indicate the number of bytes just written to the transmit FIFO specified by EPINDEX. This
register is endpoint indexed. TXCNTL should be written after TXCNTH. TXCNTL write increments TXFIF, vali-
dating the data set just written.
Note: To send a status stage after a control write, no data control command, or a null packet, write 0 to TXCNT.
TXDAT7
Bit 15
15:10
Bit 7
Bit 7
Bit 7
BC7
7:0
Bit
6:0
9:0
Bit
Bit
—
—
7
TXCNTH = 02H, TXCNTL = 01H; Default: TXCNTH = 0000 0000B; TXCNTL = 0000 0000B
TXDAT[7:0] Transmit Data Byte (Write Only). To write data to the transmit FIFO, write to this
Symbol
Symbol
Symbol
BC[9:0]
TXDAT6
A[6:0]
Bit 14
Bit 6
Bit 6
Bit 6
BC6
—
—
A6
(continued)
Reserved. Write 0 to this bit. Reads always return 0.
7-Bit Programmable Function Address. This register is written by firmware as a
result of commands received via endpoint 0.
Reserved. Write 0s to these bits. Reads always return 0s.
Transmit Byte Count (Write, Conditional Read). 10-bit, ring buffer. These bits store
transmit byte count (TXCNT).
register. The write pointer is incremented automatically after a write.
TXDAT5
Bit 13
Bit 5
Bit 5
Bit 5
BC5
A5
—
—
TXDAT4
Bit 12
Bit 4
Bit 4
Bit 4
BC4
A4
R/W
W
Function/Description
Function/Description
TXDAT3
Function/Description
Bit 11
Bit 3
Bit 3
Bit 3
BC3
A3
R/W
TXDAT2
Bit 10
Bit 2
Bit 2
Bit 2
BC2
A2
USB Device Controller
TXDAT1
Bit 1
Bit 1
Bit 9
Bit 1
BC9
BC1
A1
R/W
USS-820D
TXDAT0
Bit 0
Bit 0
Bit 8
Bit 0
BC8
BC0
A0
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