Datasheet

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