AD5258

Rev. 0 | Page 17 of 24

WRITE MODES

Table 8. Writing to RDAC Register

S

7-Bit Device Address

(See Table 5)

0

SA

0

0

0

0

0

0

0

0

SA

X

X

D5

D4

D3

D2

D1

D0

SA

P

Slave Address Byte

Instruction Byte

Data Byte

Table 9. Writing to EEPROM Register

S

7-Bit Device Address

(See Table 5)

0

SA

0

0

1

0

0

0

0

0

SA

X

X

D5

D4

D3

D2

D1

D0

SA

P

Slave Address Byte

Instruction Byte

Data Byte

The wiper’s default value, prior to programming the EEPROM, is midscale.

Table 10. Activating/Deactivating Software Write Protect

S

7-Bit Device Address

(See Table 5)

0

SA

0

1

0

0

0

0

0

0

SA

0

0

0

0

0

0

0

WP

SA

P

Slave Address Byte

Instruction Byte

Data Byte

In order to activate the write protection mode, the WP bit in Table 10 must be logic high. In order to deactivate the write protection, the

command must be sent again except with the WP in logic zero state.

READ MODES

Read modes are referred to as traditional because the first two

bytes for all three cases are “dummy” bytes which function to

place the pointer towards 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,

then 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

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