L-USS820FD-DB AGERE [Agere Systems], L-USS820FD-DB Datasheet - Page 19

• Manufacturer Part Number: L-USS820FD-DB
• Description: USB Device Controller
• Manufacturer: AGERE [Agere Systems]

Data Sheet, Rev. 1
August 2004
Agere Systems Inc.
Register Interface
Table 17. Start of Frame Low Register (SOFL)—Address: 0EH; Default: 0000 0000B
This register contains the lower 8 bits of the 11-bit time stamp received from the host.
* S = shared bit. See Special Firmware Action for Shared Register Bits section.
Table 18. Endpoint Index Register (EPINDEX)—Address: 0AH; Default: 0000 0000B
This register identifies the endpoint pair. The register’s contents select the transmit and receive FIFO pair and
serve as an index to endpoint-specific special function registers (SFRs).
* The EPINDEX register identifies the endpoint pair and selects the associated transmit and receive FIFO pair. The value in this register plus
SFR addresses select the associated band of endpoint-indexed SFRs (TXDAT, TXCON, TXFLG, TXCNTH/L, RXDAT, RXCON, RXFLG,
RXCNTH/L, EPCON, TXSTAT, and RXSTAT).
Bit 7
Bit 7
TS7
7:0
7:3
2:0
Bit
Bit
EPINX[2:0] Endpoint Index.
Symbol
Symbol
TS[7:0]
Bit 6
Bit 6
TS6
—
(continued)
Time Stamp Received from Host. This time stamp is valid only if the SOFACK bit in
the SOFH register is set. TS[7:0] are the lower 8 bits of the 11-bit frame number
issued with an SOF token. The time stamp remains at its previous value if an artificial
SOF is generated, and it is up to firmware to update it. These bits are set and cleared
by hardware.
Reserved. Write 0s to these bits. Reads always return 0s.
EPINDEX*
0000 0000
0000 0001
0000 0010
0000 0011
0000 0100
0000 0101
0000 0110
0000 0111
The EPINDEX register must not be changed during a sequence of RXDAT reads of a
particular data set. See the Receive FIFO section for more details.
Bit 5
Bit 5
TS5
—
—
Bit 4
Bit 4
TS4
Function Endpoint
Function Endpoint 0
Function Endpoint 1
Function Endpoint 2
Function Endpoint 3
Function Endpoint 4
Function Endpoint 5
Function Endpoint 6
Function Endpoint 7
R/W (S*)
Function/Description
Function/Description
Bit 3
Bit 3
TS3
EPINX2
Bit 2
Bit 2
TS2
USB Device Controller
EPINX1
Bit 1
Bit 1
R/W
TS1
USS-820FD
EPINX0
Bit 0
Bit 0
TS0
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