WM8998 Datasheet, PDF (245/307 Pages) Wolfson Microelectronics plc – High Performance Audio Hub CODEC

Production Data
WM8998
REGISTER
BIT
ADDRESS
LABEL
DEFAULT
DESCRIPTION
7:0 WSEQ_DATA0
[7:0]
00h
Data to be written in this sequence
step. When the data width is less
than 8 bits, then one or more of the
MSBs of WSEQ_DATAn are ignored.
It is recommended that unused bits
be set to 0.
Table 110 Write Sequencer Control - Programming a Sequence
SEQUENCER MEMORY DEFINITION
The Write Sequencer memory defines up to 256 write operations; these are indexed as 0 to 255 in the
sequencer memory map.
Following Power-On Reset (POR), the sequencer memory will contain the Boot Sequence, and the
OUT1, OUT2, OUT3, OUT4 signal path enable/disable sequences. The remainder of the sequencer
memory will be undefined on power-up. See the “Applications Information” section for a summary of
the WM8998 memory reset conditions.
User-defined sequences can be programmed after power-up. Note that all control sequences are
maintained in the sequencer memory through Hardware Reset, Software Reset and in Sleep mode.
The default control sequences can be overwritten in the sequencer memory, if required. Note that the
headphone and earpiece output path enable registers (HPx_ENA, LINEx_ENA, EP_ENA,
SPKOUTx_ENA) will always trigger the Write Sequencer (at the pre-determined start index
addresses).
Writing ‘1’ to the WSEQ_LOAD_MEM bit will clear the sequencer memory to the POR state.
REGISTER
BIT
ADDRESS
LABEL
DEFAULT
DESCRIPTION
R24 (0018h)
Write
Sequencer
Ctrl 2
0
WSEQ_LOAD_
MEM
0
Writing a 1 to this bit resets the
sequencer memory to the POR state.
Table 111 Write Sequencer Control - Load Memory Control
User-defined sequences must be assigned space within the Write Sequencer memory. The start
index for the user-defined sequences is configured using the registers described in Table 105 and
Table 106. The Boot Sequence has a fixed start address, as referenced in Table 108.
The sequencer memory is illustrated in Figure 74. The pre-programmed sequencer index locations
are highlighted. User-defined sequences should be programmed in other areas of the sequencer
memory.
Any user-defined additions to the Boot Sequence should be configured at index location 208 upwards.
The final step of the Boot Sequence must be programmed with WSEQ_DELAYn = 0xF, identifying the
end of the sequence. If there are no user-defined additions to the Boot Sequence, then the default
values of sequencer index 208 should be left unchanged.
Other user-defined sequences can be configured at index locations 209 upwards (excluding any index
locations that have been allocated to the Boot Sequence).
w
PD, October 2014, Rev 4.0
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