WMS7201010S WINBOND [Winbond], WMS7201010S Datasheet - Page 8

• Manufacturer Part Number: WMS7201010S
• Description: 256-TAP NON-VOLATILE DIGITAL POTENTIOMETER
• Manufacturer: WINBOND [Winbond]

The WMS7201 has four NVMEM positions available for storing the output buffer operating mode and
the potentiometer setting. These NVMEM positions can be directly written through the SPI using a
write command (#5) with address and data bytes. Another command (#7) is available that stores the
current output buffer operating mode and potentiometer settings into the selected NVMEM position.
Bit A3 and A2 in the instruction byte decide which NVMEM position is used. (See Table 5)
The potentiometer is loaded with the value stored in the NVMEM position 0 on power up.
Write-Protect ( WP ) disables any changes of current content in the NVMEM regardless of the
commands, except that NVMEM setting can be retrieved using commands 4, 6 of Table
Write-Protect ( WP ) pin provides hardware NVMEM protection feature with WP tied to Vss. WP ,
which is active at logic LOW, should be tied directly to V
available on the 10-pin package.
Reading and writing to NVMEM requires an internal access cycle to complete before the next
command can be sent.
Read Tap Register (#2)
Read NVMEM (#4)
Program NVMEM (#5)
Load Tap Register(#6)
Program NVMEM with Tap Register (#7)
7.3. N
7.4 F
7.3.1 Write Protect of NVMEM
LOW
ON
-V
C
OLATILE
ONTROL
M
EMORY
(NVMEM)
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DD
if it is not being used. This function is only
WMS7201
5.
Therefore,