Datasheet
Data Sheet AD5258
Rev. D | Page 17 of 24
READ MODES
Read modes are referred to as traditional because the first two
bytes for all three cases are dummy bytes that function to place
the pointer toward the correct register. This is the reason for the
repeat start. In theory, this step can be avoided if the user is
interested in reading a register that was previously written to.
For example, if the EEPROM was just written to, the user can
skip the two dummy bytes and proceed directly to the slave
address byte followed by the EEPROM readback data.
Table 11. Traditional Readback of RDAC Register Value
S
7-Bit Device Address
(See Table 5)
0
SA 0 0 0 0
0
0
0
0 SA
S
7-Bit Device Address
(See Table 5)
1
SA
X
X D5
D4
D3
D2
D1
D0
NA
P
Slave Address Byte Instruction Byte Slave Address Byte Read-back Data
↑
Repeat Start
Table 12. Traditional Readback of Stored EEPROM Value
S
7-Bit Device Address
(See Table 5)
0
SA 0 0 1 0 0 0 0 0 SA S
7-Bit Device Address
(See Table 5)
1 SA X X D5 D4 D3 D2 D1 D0 NA P
Slave Address Byte Instruction Byte Slave Address Byte Read-back Data
↑
Repeat Start
STORE/RESTORE MODES
Table 13. Storing RDAC Value to EEPROM
S
7-Bit Device Address
(See Table 5) 0 SA 1 1 0 0 0 0 0 0 SA P
Slave Address Byte Instruction Byte
Table 14. Restoring EEPROM to RDAC
1
S
7-Bit Device Address
(See Table 5)
0 SA 1 0 1 0 0 0 0 0 SA P
Slave Address Byte Instruction Byte
1
User should issue an NOP command immediately after this command to conserve power.