WM8945
Production Data
Figure 41 Single Register Read from Specified Address
Figure 42 Multiple Register Write to Specified Address using Auto-increment
Figure 43 Multiple Register Read from Specified Address using Auto-increment
Figure 44 Multiple Register Read from Last Address using Auto-increment
Multiple Write and Multiple Read operations enable the host processor to access sequential blocks of
the data in the WM8945 register map faster than is possible with single register operations. The auto-
increment option is enabled when the AUTO_INC register bit is set. This bit is defined in Table 66.
Auto-increment is disabled by default.
3-WIRE (SPI) CONTROL MODE
The 3-wire control interface uses the C¯¯S, SCLK and SDA pins.
In 3-wire control mode, a control word consists of 32 bits. The first bit is the read/write bit (R/W),
which is followed by 15 address bits (A14 to A0) that determine which control register is accessed.
The remaining 16 bits (B15 to B0) are data bits, corresponding to the 16 bits in each control register.
In 3-wire mode, every rising edge of SCLK clocks in one data bit from the SDA pin. The data is
latched on the 32nd falling edge of SCLK after 32 bits of data have been clocked into the device.
In Write operations (R/W=0), all SDA bits are driven by the controlling device.
PD, May 2011, Rev 4.1
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WOLFSON [ WOLFSON MICROELECTRONICS PLC ]
