Datasheet

1
StartBy
Master
ACKBy
ADS7924
ACKBy
ADS7924
StartBy
Master
ACKBy
ADS7924
ACKBy
Master
(2)
From
ADS7924
1 9 1
9
1 9 1
9
SDA
SCL
0 0 1 R/W
0
(2)
0 0 P4
(3)
P3 P2 P1 P0
¼
SDA
(Continued)
SCL
(Continued)
1 0 0 1
0 A0
(1)
0
A0
(1)
R/W
D7 D6 D5 D4 D3 D2 D1 D0
StopBy
Master
0
0
Frame2PointerAddressByte
Frame3SlaveAddressByte
Frame4DataByte
Frame1SlaveAddressByte
Frame1SlaveAddressByte Frame2RegisterDataByte
1
StartBy
Master
ACKBy
ADS7924
ACKBy
ADS7924
1 9 1
9
SDA
SCL
0 0 1 R/W
D7 D6 D5 D4 D3 D2 D1 D0
0 A0
(1)
StopBy
Master
0
ADS7924
SBAS482A –JANUARY 2010–REVISED MAY 2010 www.ti.com
READING THE REGISTERS The master may issue a START condition and send
the slave address byte with the R/W bit high to begin
To read a specific register from the ADS7924, the
the read. Note that if the previously selected register
master must first write the appropriate value to the
is to be read again there is no need to update the
pointer address. The pointer address is written
pointer address. Figure 32 to Figure 34 show
directly after the slave address byte, low R/W bit, and
examples of register reads.
a successful slave acknowledgment. The MSB of the
pointer address is the INC bit. When set to '1', the
register address is automatically incremented after
every register read which allows convenient reading
of multiple registers. Set INC to '0' when reading a
single register.
(1) The value of A0 is determined by the A0 pin.
(2) When INC is set to '0', the address pointer remains unchanged after a read.
(3) Bits P[4:0] point to the register to be read.
Figure 32. Reading a Single Register Timing Diagram
(1) The value of A0 is determined by the A0 pin.
Figure 33. Reading a Previously Addressed Register Timing Diagram
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