WM5102 datasheet(257/334 Pages) WOLFSON

257 / 334 page

Production Data

WM5102

PD, June 2014, Rev 4.2

257

CONTROL WRITE SEQUENCER

The Control Write Sequencer is a programmable unit that forms part of the WM5102 control interface

logic. It provides the ability to perform a sequence of register write operations with the minimum of

demands on the host processor - the sequence may be initiated by a single operation from the host

processor and then left to execute independently.

Default sequences for pop-suppressed start-up and shut-down of each headphone/earpiece output

driver are provided (these are scheduled automatically when the respective output paths are enabled

or disabled). Other control sequences can be programmed, and may be associated with Jack Detect,

Wake-Up or Sample Rate Detection functions - these sequences are automatically scheduled

whenever a corresponding event is detected.

When a sequence is initiated, the sequencer performs a series of pre-defined register writes. The

‘start index’ of a control sequence within the sequencer’s memory may be commanded directly by the

host processor. In the case of a headphone or earpiece enable/disable event, or sequences

associated with Jack Detect, Sleep Control or Sample Rate Detection, the applicable ‘start index’ is

held in a user-programmed control register for each sequence.

The Control Write Sequencer may be triggered in a number of ways, as described above. Multiple

sequences will be queued if necessary, and each is scheduled in turn. When all of the queued

sequences have completed, the sequencer stops, and an Interrupt status flag is asserted.

A valid clock (SYSCLK) must be enabled whenever a Control Write Sequence is scheduled. See

“Clocking and Sample Rates” for further details.

INITIATING A SEQUENCE

The Register fields associated with running the Control Write Sequencer are described in Table 112.

The Write Sequencer is enabled using the WSEQ_ENA bit. The index location of the first command in

the selected sequence is held in the WSEQ_START_INDEX register.

Writing a ‘1’ to the WSEQ_START bit commands the sequencer to execute a control sequence,

starting at the given index. Note that, if the sequencer is already running, then the WSEQ_START

command will be queued, and will be executed later when the sequencer becomes available.

The Write Sequencer can be interrupted by writing a ‘1’ to the WSEQ_ABORT bit. Note that this

command will only abort a sequence that is currently running; if other sequence commands are

pending and not yet started, these sequences will not be aborted by writing to the WSEQ_ABORT bit.

The Write Sequencer stores up to 256 register write commands. These are defined in Registers

R12288 (3000h) to R12799 (31FFh). Each of the 256 possible commands is defined in 2 control

registers - see Table 117 for a description of these registers.

WM5102 Datasheet(PDF) 257 Page - Wolfson Microelectronics plc