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 RDAC1

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.