WM8860 datasheet(30/184 Pages) WOLFSON

30 / 184 page

WM8860

Pre-Production

PP, April 2011, Rev 3.2

Channel synchronisation between channels is only guaranteed where stream packets are received by

the WM8860 after all converters in a multi-channel stream have had their stream ID assigned.

Mono Streams

All converters are stereo. Where an input converter (eg. ADC1) is associated with a mono stream,

only the left channel (channel 0) will be sent on the HDA Link.

In mono mode, right channel modules in the ADC will be disabled to save power.

Where an output converter (eg. DAC1, S/PDIF Tx) is associated with a mono stream, both left and

right channels render the same samples. If both left and right DAC outputs are not desired, the

unwanted channel can be muted.

A stream is assumed to be mono when its Chan control in the Stream Format Verb is set to 0. The

Channel control in the Converter Stream, Channel Verb should be set to 0, although any setting of

this register gives the same behaviour in mono mode.

ILLEGAL REGISTER VALUES

Should the user set verb registers to illegal, unsupported or reserved values, WM8860 behaviour is

undefined.

Writing to Reserved registers has no effect.

RESPONSE FIELD

Valid Bit

Bit [35] of the Response Field is defined as the Valid Bit. Section 7.3.1 of the HDA specification

states: “A 1 in the Valid bit position indicates the Response Filed contains a valid response, which the

controller will place in the RIRB; a 0 indicates there is no response.”

The WM8860 will set the Valid Bit for all responses, except null responses.

We define a null response as a response to a command that contains an invalid verb (a command

where NID=0h, and Verb=0h), or a response to a command with a CODEC address (CAd) that does

not match the WM8860 CAd. Either of these commands can be considered as a null command.

We define a non-defined command as a command that has no meaning (i.e. a NID that is not within

the WM8860, or a Verb ID that is not supported for the given node). The WM8860 will set the Valid

Bit for non-defined commands.

WM8860 Datasheet(PDF) 30 Page - Wolfson Microelectronics plc