wms7202 Winbond Electronics Corp America, wms7202 Datasheet - Page 13

• Manufacturer Part Number: wms7202
• Description: 256-tap Dual-channel Non-volatile Digital
• Manufacturer: Winbond Electronics Corp America

The chip is in SLEEP mode after:
Before any operations can be performed the WAKE UP command must be sent.
When a SLEEP command is sent, the chip retains its resistor settings as long as the chip is powered
up but cannot accept any other commands than a WAKE UP command.
The commands above control the entire chip. There is no way to independently power on or off
individual potentiometers.
The microcontroller can write a value directly into the tap register or send an increment or decrement
command to control the tap register. Alternatively, the contents of an NVMEM location can be written
to the tap register. The only way to change the output buffer mode is to write the desired value of bit
D8 into an NVMEM location and then load the corresponding NVMEM location into the tap register.
Inst.
No.
11
10
13
1
5. 24 clock pulses are sent for each command. SDI must be valid on the rising edge of the clock,
6. Take CS HIGH after the command has completed.
7. If command 2, 4, 5, 6 or 7 is sent, wait for the R/B pin to go HIGH before sending the next
x
x
x
SDO is valid on the falling edge of the clock or CS .
command.
7.8.2 Wake Up/Sleep/Power Commands
V
A Power on Reset command is sent
A SLEEP command is sent
Command
Name:
Wake Up
Sleep
Power on Reset
NOP
7.8.3 Write to Tap Register (TR)
DD
is applied
Command Byte
0 0 0 1 x x x x
1 0 0 0 x x x x
1 0 0 1 x x x x
0 0 0 0 x x x x
TABLE 6 – POWER RELATED COMMANDS
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
- 13 -
Data Byte 2
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
Publication Release Date: January 2003
Comment
save mode
Reset Chip
Wake Up entire chip
Send chip into power
Dummy instruction
WMS7202
Revision 1.1