EVAL-AD5254EBZ Analog Devices Inc, EVAL-AD5254EBZ Datasheet - Page 16

• Manufacturer Part Number: EVAL-AD5254EBZ
• Description: Evaluation Board
• Manufacturer: Analog Devices Inc

Specifications of EVAL-AD5254EBZ

• Main Purpose: Digital Potentiometer
• Utilized Ic / Part: AD5245
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Secondary Attributes: -
• Embedded: -
• Primary Attributes: -
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

AD5253/AD5254
RDAC/EEMEM Write
Setting the wiper position requires an RDAC write operation.
The single write operation is shown in Figure 27, and the
consecutive write operation is shown in Figure 28. In the
consecutive write operation, if the RDAC is selected and the
address starts at 0, the first data byte goes to RDAC0, the second
data byte goes to RDAC1, the third data byte goes to RDAC2,
and the fourth data byte goes to RDAC3. This operation can be
continued for up to eight addresses with four unused addresses;
it then loops back to RDAC0. If the address starts at any of the
eight valid addresses, N, the data first goes to RDAC_N,
RDAC_N + 1, and so on; it loops back to RDAC0 after the
eighth address. The RDAC address is shown in
While the RDAC wiper setting is controlled by a specific
RDAC register, each RDAC register corresponds to a specific
EEMEM location, which provides nonvolatile wiper storage
functionality. The addresses are shown in Table 7. The single
and consecutive write operations also apply to EEMEM write
operations.
There are 12 nonvolatile memory locations: EEMEM4 to
EEMEM15. Users can store 12 bytes of information, such as
memory data for other components, look-up tables, or system
identification information.
In a write operation to the EEMEM registers, the device disables
the I
polling is required to determine the completion of the write
cycle. See the EEMEM Write-Acknowledge Polling section.
RDAC/EEMEM Read
The AD5253/AD5254 provide two different RDAC or EEMEM
read operations. For example, Figure 29 shows the method of
reading the RDAC0 to RDAC3 contents without specifying the
address, assuming Address RDAC0 was already selected in the
previous operation. If an RDAC_N address other than RDAC0
was previously selected, readback starts with Address N,
followed by N + 1, and so on.
Figure 30 illustrates a random RDAC or EEMEM read
operation. This operation allows users to specify which RDAC
or EEMEM register is read by issuing a dummy write command
to change the RDAC address pointer and then proceeding with
the RDAC read operation at the new address location.
2
C interface during the internal write cycle. Acknowledge
Table 6
.
Rev. B | Page 16 of 32
Table 7. Addresses for Writing (Storing) RDAC Settings and
User-Defined Data to EEMEM Registers
(R/ W = 0, CMD/ REG = 0, EE/ RDAC = 1)
A4
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Table 8. Addresses for Reading (Restoring) RDAC Settings
and User Data from EEMEM
(R/ W = 1, CMD/ REG = 0, EE/ RDAC = 1)
A4
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
1
Users can store any of the 64 RDAC settings for AD5253 or any of the 256
RDAC settings for the AD5254 directly to the EEMEM. This is not limited to
current RDAC wiper setting.
A3
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
A3
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
A2
0
0
0
0
1
1
1
1
0
0
0
0
1
1
1
1
A2
0
0
0
0
1
1
1
1
0
0
0
0
1
1
1
1
A1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
A1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
A0
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
A0
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
Data Byte Description
Read RDAC0 setting from EEMEM0
Read RDAC1 setting from EEMEM1
Read RDAC2 setting from EEMEM2
Read RDAC3 setting from EEMEM3
Read User data from EEMEM4
Read user data from EEMEM5
Read user data from EEMEM6
Read user data from EEMEM7
Read user data from EEMEM8
Read user data from EEMEM9
Read user data from EEMEM10
Read user data from EEMEM11
Read user data from EEMEM12
Read user data from EEMEM13
Read user data from EEMEM14
Read user data from EEMEM15
Data Byte Description
Store RDAC0 setting to EEMEM0
Store RDAC1 setting to EEMEM1
Store RDAC2 setting to EEMEM2
Store RDAC3 setting to EEMEM3
Store user data to EEMEM4
Store user data to EEMEM5
Store user data to EEMEM6
Store user data to EEMEM7
Store user data to EEMEM8
Store user data to EEMEM9
Store user data to EEMEM10
Store user data to EEMEM11
Store user data to EEMEM12
Store user data to EEMEM13
Store user data to EEMEM14
Store user data to EEMEM15
1
1
1
1