Datasheet

TUSB7320, TUSB7340
www.ti.com
SLLSE76EMARCH 2011 REVISED JULY 2011
4.50 Serial Bus Index Register
The value written to the Serial Bus Index register represents the byte address of the byte being read or
written from the serial bus device. The Serial Bus Index register must be written before the before initiating
a serial bus cycle by writing to the Serial Bus Slave Address register. This register is reset by a PCI
Express reset (PERST#), a GRST#, or the internally-generated power-on reset.
PCI register offset: B1h
Register type:Read/Write
Default value: 00h
Table 4-74. PCI Register B1h
Bit No. 7 6 5 4 3 2 1 0
Reset State 0 0 0 0 0 0 0 0
4.51 Serial Bus Slave Address Regsiter
The Serial Bus Slave Address register is used to indicate the address of the device being targeted by the
serial bus cycle. This register also indicates if the cycle will be a read or a write cycle. Writing to this
register initiates the cycle on the serial interface. This register is reset by a PCI Express reset (PERST#),
a GRST#, or the internally-generated power-on reset.
PCI register offset: B2h
Register type:Read/Write
Default value: 00h
Table 4-75. PCI Register B2h
Bit No. 7 6 5 4 3 2 1 0
Reset State 0 0 0 0 0 0 0 0
Table 4-76. Serial Bus Slave Address Register Description
(1)
Bit Field Name Access Description
Serial Bus Slave Address. This bit field represents the slave address of a
7:1 SLAVE_ADDR rw
read or write transaction on the serial interface.
Read/Write Command. This bit is used to determine if the serial bus
cycle will be a read or a write cycle.
0 RW_CMD rw
0 A single byte write is requested.
1 A single byte read is requested.
(1) Bits marked with are reset by a PCI Express reset (PERST#), a GRST#, or the internally-generated power-on reset.
4.52 Serial Bus Control and Status Register
The Serial Bus Control and Status register is used to control the behavior of the Serial bus interface. This
register also provides status information about the state of the serial bus. This register is reset by a PCI
Express reset (PERST#), a GRST#, or the internally-generated power-on reset.
PCI register offset: B3h
Register type:Read/Write, Read-Only, Read/Clear
Default value: 00h
Copyright © 2011, Texas Instruments Incorporated CLASSIC PCI CONFIGURATION SPACE 53
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