WMS7201010S WINBOND [Winbond], WMS7201010S Datasheet - Page 15

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

Inst.
No.
4
2
1
The contents of the tap register or any NVMEM location can be read back through the SDO pin. When
a command is sent, the data is clocked out on the falling edge of the clock. Since daisy-chain
operation requires data from one command to be clocked out when the next command arrives, any
read command must be followed by another command to get the correct data on the SDO pin.
To read the contents of either the tap register or a NVMEM location, the following sequence must be
followed.
Command
Name:
Read
NVMEM
Read Tap
Register
NOP to
Read
Register
1. Send the desired read command (#2 or #4)
2. Send another command such as NOP and read the SDO pin on the falling edge of the clock.
7.8.5 Reading Tap Register and NVMEM Location (10-pin TSSOP package only)
The other command could be any command, but to make sure that the chip does not change
anything, send either another Read command or a NOP command (#1).
Command Byte
1 0 1 0 A3 A2 0 0
1 1 0 0 x x 0 0
0 0 0 0 x x x x
TABLE 9 – READING THE TAP REGISTER
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 D8
- 15 -
Data Byte 2
D7 D6 D5 D4 D3 D2 D1 D0
x x x x x x x x
x x x x x x x x
Publication Release Date: January 2003
WMS7201
Comment
Read the value of the
selected NVMEM
location
Read the value of the
selected tap register
Output data to SDO
pin
Revision 1.1