wms7201 Winbond Electronics Corp America, wms7201 Datasheet - Page 14

• Manufacturer Part Number: wms7201
• Description: 256-tap Non-volatile Digital Potentiometer
• Manufacturer: Winbond Electronics Corp America

Inst.
No
12
5
7
Inst.
No.
3
8
9
6
Command
Name
Erase
NVMEM
Program
NVMEM
Program
NVMEM
with Tap
Register
The value stored in the NVMEM location is 9 bits, the 8 bits (D7-D0) of the tap register plus 1 bit (D8)
of the output buffer mode. The NVMEM position must be erased before writing to it. There are two
ways to program a value into NVMEM.
Write a value directly from the microcontroller.
Load the current potentiometer setting into NVMEM.
For programming NVMEM, the following sequence must be followed:
Up
Down
Comman
d Name:
Write to
Tap
Register
Load Tap
Register
1. Erase word at NVMEM location
2. Program word at NVMEM location
7.8.4 Programming Non-Volatile Memory (NVMEM)
Command Byte
1 1 0 1 A3 A2 0 0
0 0 1 0 A3 A2 0 0
0 0 1 1 A3 A2 0 0
Command Byte
0 1 0 0 x x 0 0
0 1 1 1 x x 0 0
1 1 1 1 x x 0 0
1 0 1 1 A3 A2 0 0
TABLE 7 – WRITING TO THE TAP REGISTERS
TABLE 8 – PROGRAMMING NVMEM
Data Byte 1
x x x x x x x x
x x x x x x x D8
x x x x x x x x
Data Byte 1
x x x x x x x x
x x x x x x x x
x x x x x x x x
x x x x x x x x
- 14 -
Data Byte 2
x x x x x x x x
x x x x x x x x
D7 D6 D5 D4 D3 D2 D1 D0
Data Byte 2
x x x x x x x x
x x x x x x x x
D7 D6 D5 D4 D3 D2 D1 D0
x x x x x x x x
WMS7201
Comment
Erases the 9 bit word
pointed to by A3, A2, A1
and A0.
Writes a value to the
NVMEM register.
Takes the current
potentiometer settings and
saves in the selected
NVMEM location.
Comment
Writes a value to the
tap register.
Increment tap
register value by one
Decrement tap
register value by one
NVMEM location into
the tap register
Load the selected