Production Data
WM8945
Power Down:
ACTION
LABEL
REGISTER[BITS]
SPKR_PGA_ENA = 1
SPKL_PGA_ENA = 1
SPKR_VOL = 00h
SPKL_VOL = 00h
DACR_MUTE = 1
DACL_MUTE = 1
DACR_VOL = 0
R3 (03h) [13]
R3 (03h) [12]
R47 (2Fh) [5:0]
R48 (30h) [5:0]
R24 (18h) [8]
R23 (17h) [8]
R24 (18h) [7:0]
R23 (17h) [7:0]
Mute speaker PGA and DAC
DACL_VOL = 0
LDO_REF_SEL_FAST = 1
LDO_BIAS_SRC = 1
R53 (35h) [14]
R53 (35h) [5]
Select LDO for fast start-up
Select VMID for fast start-up
VMID_SEL = 11
R2 (02h) [1:0]
R7 (07h) [11]
R7 (07h) [7]
VMID_FAST_START =1
BIAS_SRC = 1
VMID_RAMP = 01
R7 (07h) [6:5]
Disabled VMID
VMID_ENA = 0
R7 (07h) [4]
Delay 500ms for VMID to discharge
SPKR_DISCH = 1
SPKL_DISCH = 1
LINEL_DISCH = 1
R42 (2Ah) [7]
R42 (2Ah) [6]
R42 (2Ah) [4]
Discharge outputs
Delay 50ms for outputs to discharge
LINEL_MUTE = 1
SPKR_OP_MUTE = 1
SPKL_OP_MUTE = 1
R42 (2Ah) [8]
R03 (03h) [9]
R03 (03h) [8]
Mute outputs
Disable power to speaker driver (must be
done before disabling the speaker
outputs)
SPKR_SPKVDD_ENA = 1
SPKL_SPKVDD_ENA = 1
R3 (03h) [11]
R3 (03h) [10]
SPKR_OP_ENA = 1
SPKL_OP_ENA = 1
R3 (03h) [7]
R3 (03h) [6]
Disable speaker outputs
Reset
SW_RESET
R0 (00h) [15:0]
Turn off external power supply voltages
SOFTWARE RESET AND DEVICE ID
The WM8945 can be reset by writing to Register R0. This is a read-only register, and the contents of
R0 will not be affected by writing to this Register.
The Device ID can be read back from Register R0. The Chip Revision ID can be read back from
Register 1, as described in Table 71.
REGISTER
ADDRESS
BIT
LABEL
DEFAULT
DESCRIPTION
R0 (00h)
15:0
SW_RESET
[15:0]
Writing to this register resets all registers
to their default state.
6229h
Software
Reset/Chip
ID 1
Reading from this register will indicate
device family ID 6229h.
R1 (01h)
3:0
CHIP_REV [3:0]
Reading from this register will indicate
the Revision ID.
Revision
Number
Table 71 Chip Reset and ID
PD, May 2011, Rev 4.1
107
w
WOLFSON [ WOLFSON MICROELECTRONICS PLC ]
