AD5251 Analog Devices, AD5251 Datasheet - Page 13

• Manufacturer Part Number: AD5251
• Description: (AD5251 / AD5252) Dual 64-and 256-Position I2C Nonvolatile Memory Digital Potentiometers
• Manufacturer: Analog Devices

RDAC/EEMEM Quick Commands
The AD5251/AD5252 feature 12 quick commands that facilitate
easy manipulation of RDAC wiper settings and provide RDAC-
to-EEMEM storing and restoring functions. The command
Table 9. RDAC-to-EEMEM Interface and RDAC Operation Quick Command Bits (CMD/ REG = 1, A2 = 0)
C3
0
0
0
0
0
0
0
0
1
1
1
1
1
:
1
1
Table 10. Address Table for Reading Tolerance (CMD/ REG = 0, EE/ RDAC = 1, A4 = 1)
A4
0
:
1
1
1
1
1
1
1
This command leaves the device in the EEMEM read power state, which consumes power. Users should issue the NOP command to return the device to the idle state.
A3
0
:
1
1
1
1
1
1
1
C2
0
0
0
0
1
1
1
1
0
0
0
0
1
:
1
A2
0
:
0
0
0
1
1
1
1
C1
0
0
1
1
0
0
1
1
0
0
1
1
0
:
1
1
1
A1
0
:
0
1
0
0
1
S = START CONDITION
P = STOP CONDITION
A = ACKNOWLEDGE (SDA LOW)
A = NOT ACKNOWLEDGE (SDA HIGH)
AD1, AD0 = I
R/W = READ ENABLE BIT, LOGIC HIGH/WRITE ENABLE BIT, LOGIC LOW
CMD/REG = COMMAND ENABLE BIT, LOGIC HIGH/REGISTER ACCESS BIT, LOGIC LOW
C3, C2, C1, C0 = COMMAND BITS
A2, A1, A0 = RDAC/EEMEM REGISTER ADDRESSES
S
FROM MASTER TO SLAVE
FROM SLAVE TO MASTER
A0
0
:
1
0
1
0
1
0
1
0
RDAC SLAVE ADDRESS
C0
0
1
0
1
0
1
0
1
0
1
0
1
0
:
1
1
2
0
C DEVICE ADDRESS BITS. MUST MATCH WITH THE LOGIC STATES AT PINS AD1, AD0
Data Byte Description
Reserved
Reserved
Sign and 7-bit integer values of RDAC1 tolerance (read only)
8-bit decimal value of RDAC1 tolerance (read only)
Reserved
Reserved
Sign and 7-bit integer values of RDAC3 tolerance (read only)
8-bit decimal value of RDAC3 tolerance (read only)
1
Figure 11. RDAC Quick Command Write (Dummy Write)
1
Command Description
NOP
Restore EEMEM (A1, A0) to RDAC (A1, A0)
Store RDAC (A1, A0) to EEMEM (A1, A0)
Decrement RDAC (A1, A0) 6 dB
Decrement all RDACs 6 dB
Decrement RDAC (A1, A0) one step
Decrement all RDACs one step
Reset: Restore EEMEMs to all RDACs
Increment RDACs (A1, A0) 6 dB
Increment all RDACs 6 dB
Increment RDACs (A1, A0) one step
Increment all RDACs one step
Reserved
Reserved
A
D
1
A
D
0
0 WRITE
0
A
Rev. 0 | Page 13 of 28
1 CMD
CMD/
REG
C
3
C
2
format is shown in Figure 11 and the command descriptions are
shown in Table 9.
C
1
C
0
A
2
A
1
A
0
1
A
P
AD5251/AD5252