Rainbow Electronics MAX5499 User Manual
Page 15
MAX5494–MAX5499
10-Bit, Dual, Nonvolatile, Linear-Taper
Digital Potentiometers
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15
ACTION
WIPER
REGISTER 1
UPDATED
0
0
0
0
0
0
0
1
D9 D8 D7 D6
D5 D4 D3 D2
D1 D0
1
2
3
4
5
6
7
8
9
10
11 12 13
14
15
16
17
18
19 20 21 22
23
24
SCLK
DIN
X
X
X
X
X
X
CS
C1 C0
RA1 RA0
ACTION
0
0
0
1
0
0
0
1
D9 D8 D7 D6
D5 D4 D3 D2
D1 D0
1
2
3
4
5
6
7
8
9
10
11 12 13
14
15
16
17
18
19 20 21 22
23
24
SCLK
DIN
X
X
X
X
X
X
CS
C1 C0
RA1 RA0
WRITE NV
REGISTER 1
(DEVICE IS BUSY)
t
BUSY
Figure 8. Write Wiper Register 1
Figure 9. Write NV Register 1
The “write wiper register” command writes data to the
volatile random access memory (RAM), leaving the NV
registers unchanged. When the device powers up, the
data stored in the NV registers transfers to the wiper
register, moving the wiper to the stored position. Figure
8 shows how to write data to wiper register 1.
Write NV Register
The “write NV register” command (C1, C0 = 01) stores
the position of the wiper to the NV registers for use at
power-up. Alternatively, the “copy wiper register to NV
register” command writes to the NV register. Writing to
the NV register does not affect the position of the
wipers. The operation takes up to 12ms (max) after CS
goes high to complete and no other operation should
be performed until completion. Figure 9 shows how to
write data to the NV register 1.
Copy Wiper Register to NV Register
The “copy wiper register to NV register” command (C1,
C0 = 10) stores the current position of the wiper to the
NV register for use at power-up. Figure 10 shows how
to copy data from wiper register 1 to NV register 1.