WMS7204

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TABLE 7 – WRITING TO THE TAP REGISTERS

Inst.

No.

Command

Name:

Command Byte

Data Byte 1

Data Byte 2

Comment

3

Write to

Tap

Register

0 1 0 0 x x A1 A0

x x x x x x x x

D7 D6 D5 D4 D3 D2 D1 D0

Writes a value to

the tap register of

the selected

channel

8

Up

0 1 1 1 x x A1 A0

x x x x x x x x

x x x x x x x x

Increment tap

register value by

one

9

Down

1 1 1 1 x x A1 A0

x x x x x x x x

x x x x x x x x

Decrement tap

register value by

one

6

Load Tap

Register

1 0 1 1 A3 A2 A1 A0

x x x x x x x x

x x x x x x x x

Load the selected

NVMEM location

into the 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.

TABLE 8 – PROGRAMMING NVMEM

Inst.

No

Command

Name

Command Byte

Data Byte 1

Data Byte 2

Comment

12

Erase

NVMEM

1 1 0 1 A3 A2 A1 A0

x x x x x x x x

x x x x x x x x

Erases the 9 bit

word pointed to by

A3, A2, A1 and A0.

5

Program

NVMEM

0 0 1 0 A3 A2 A1 A0

x x x x x x x D8

D7 D6 D5 D4 D3 D2 D1 D0

Writes a value to

the selected

NVMEM register of

the selected

channel

7

Program

NVMEM with

Tap Register

0 0 1 1 A3 A2 A1 A0

x x x x x x x x

x x x x x x x x

Takes the current

potentiometer

settings and saves

in the selected

NVMEM location.

For programming NVMEM, the following sequence must be followed:

1. Erase word at NVMEM location

2. Program word at NVMEM location