4.49 Serial Bus Slave Address Register

The serial bus slave address register is for programmable serial bus byte read and write transactions. To write a byte, the serial bus data register must be programmed with the data, the serial bus index register must be programmed with the byte address, and this register must be programmed with both the 7-bit slave address and the read/write indicator bit.

On byte reads, the byte address is programmed into the serial bus index register, this register must be programmed with both the 7-bit slave address and the read/write indicator bit, and bit 5 (REQBUSY) in the serial bus control and status register (see Section 4.50) must be polled until clear. Then the contents of the serial bus data register are valid read data from the serial bus interface. See Table 4−24 for a complete description of the register contents.

Bit

7

6

5

4

3

2

1

0

 

 

 

 

 

 

 

 

 

Name

 

 

 

Serial bus slave address

 

 

 

 

 

 

 

 

 

 

 

 

Type

RW

RW

RW

RW

RW

RW

RW

RW

 

 

 

 

 

 

 

 

 

Default

0

0

0

0

0

0

0

0

Register: Serial bus slave address

Offset: B2h (function 0)

Type: Read/Write

Default: 00h

Table 4−24. Serial Bus Slave Address Register Description

BIT

SIGNAL

TYPE

 

FUNCTION

 

 

 

 

7−1 ‡

SLAVADDR

RW

Serial bus slave address. This bit field represents the slave address of a read or write transaction on the

serial interface.

 

 

 

 

 

 

 

 

 

 

Read/write command. Bit 0 indicates the read/write command bit presented to the serial bus on byte read

0 ‡

RWCMD

RW

and write accesses.

0

= A byte write access is requested to the serial bus interface.

 

 

 

 

 

 

1

= A byte read access is requested to the serial bus interface.

These bits are cleared only by the assertion of GRST.

4−36

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Texas Instruments PCI7621, PCI7411, PCI7611 Serial Bus Slave Address Register, Register Serial bus slave address, Rwcmd