WM8581 datasheet(70/94 Pages) WOLFSON

70 / 94 page

WM8581

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PP Rev 1.0 March 2006

HARDWARE CONTROL MODE

The WM8581 can be controlled in Hardware Control Mode or Software Control Mode. The method of

control is determined by the state of the HWMODE pin. If the HWMODE pin is low, Software Control

Mode is selected. If the HWMODE pin is high, Hardware Control Mode is selected.

In Hardware Control Mode the user has limited control over the features of the WM8581. Most of the

features will assume their default settings but some can be modified using external pins.

HWMODE

SWMODE

Software Control

Hardware Control

2-wire control

3-wire control

Table 68 Hardware/Software Mode Setup

DIGITAL ROUTING CONTROL

See page 22 for a more detailed explanation of the Digital Routing Options within the WM8581. In

Software Control Mode, the values of register bits DAC_SRC, PAIFTX_SRC and TXSRC configure

the signal path routing between interfaces. In hardware mode, similar control can be achieved via

pins DR1, DR2, DR3 and DR4 as detailed in Table 69 and Table 70.

DR1

DAC_SRC=S/PDIF receiver

DAC_SRC=PAIF receiver

DR2

PAIFTX_SRC=S/PDIF

receiver

PAIFTX_SRC=ADC output

Table 69 DR1 / DR2 Operation

DR4

DR3

S/PDIF TRANSMITTER

DATA SOURCE

S/PDIF received data

ADC digital output data

SAIF receiver data

PAIF receiver data

Table 70 DR3 / DR4 Operation

The Secondary Audio Interface (SAIF) is not operational in Hardware Mode.

WM8581 Datasheet(PDF) 70 Page - Wolfson Microelectronics plc