WM8804GEDS/V View Datasheet(PDF) - Cirrus Logic
Part Name
Description
MFG CO.
'WM8804GEDS/V' PDF : 66 Pages View PDF
Production Data
WM8804
Multiple consecutive register writes can be performed in 2-wire control mode by setting the CONT bit
high. This method allows the entire register map to be defined in a one continuous write operation.
Figure 12 2-Wire Serial Control Interface Multi-Write
The WM8804 has two possible device addresses, which can be selected using the CSB pin during
hardware reset.
CSB STATE
DEVICE ADDRESS IN
2-WIRE MODE
Low
High
0111010x
0111011x
Table 11 2-Wire Interface Address Selection
ADDRESS (X=R/W BIT)
X=0
X= 1
0x74
0x75
0x76
0x77
2-WIRE SERIAL CONTROL MODE -REGISTER READ-BACK
The WM8804 allows read-back of certain registers in 2-wire mode. The protocol is similar to that
used to write to the device. The controller will issue the device address followed by a write bit, the
register index will then be passed to the WM8804. At this point the controller will issue a repeated
start condition and resend the device address along with a read bit. The WM8804 will acknowledge
this and the WM8804 will become a slave transmitter. The WM8804 will transmit the data from the
indexed register on SDIN MSB first. When the controller receives the data it will not acknowledge
receipt of the data indicating that it will resume master transmitter control of SDIN. The controller will
then issue a stop command completing the read cycle. Figure 13 illustrates the read protocol.
Figure 13 2-Wire Serial Control Interface Read (CONT=0)
2-WIRE SERIAL CONTROL MODE – CONTINUOUS READ-BACK
As in 3-wire mode, there are two methods of reading back data: continuous and non-continuous
read-back. Continuous read-back is selected by setting CONT to 1. In continuous read-back mode,
the device will return the indexed register first followed by consecutive registers in increasing index
order until the controller does not acknowledge the data then issues a stop sequence. This is shown
in Figure 14
Figure 14 2-Wire Serial Interface Continuous Read-Back (CONT=1)
w
PD, Rev 4.5, March 2009
17
Share Link: 
