WM8196

Production Data

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PD Rev 4.6 October 2008

18

OUTPUT

FORMAT

MUXOP[1:0]

OUTPUT

PINS

OUTPUT

8+8-bit

multiplexed

00, 01, 10

OP[7:0]

A = d15, d14, d13, d12, d11, d10, d9, d8

B = d7, d6, d5, d4, d3, d2, d1,d0

4+4+4+4-bit

(nibble)

11

OP[7:4]

A = d15, d14, d13, d12

B = d11, d10, d9, d8

C = d7, d6, d5, d4

D = d3, d2, d1, d0

Table 2 Details of Output Data Shown in Figure 15 and Figure 16.

CONTROL INTERFACE

The internal control registers are programmable via the serial digital control interface. The register

contents can be read back via the serial interface on pin OP[7]/SDO.

Note: It is recommended that a software reset is carried out after the power-up sequence, before

writing to any other register. This ensures that all registers are set to their default values (as shown

in Table 6).

SERIAL INTERFACE: REGISTER WRITE

Figure 17 shows register writing in serial mode. Three pins, SCK, SDI and SEN are used. A six-bit

address (a5, 0, a3, a2, a1, a0) is clocked in through SDI, MSB first, followed by an eight-bit data

word (b7, b6, b5, b4, b3, b2, b1, b0), also MSB first. Each bit is latched on the rising edge of SCK.

When the data has been shifted into the device, a pulse is applied to SEN to transfer the data to the

appropriate internal register. Note all valid registers have address bit a4 equal to 0 in write mode.

SCK

SEN

SDI

a5

0

a3a2a1

a0b7b6b5

b4b3b2b1b0

Address

Data Word

Figure 17 Serial Interface Register Write

A software reset is carried out by writing to Address “000100” with any value of data, i.e. Data Word

= XXXXXXXX.

SERIAL INTERFACE: REGISTER READ-BACK

Figure 18 shows register read-back in serial mode. Read-back is initiated by writing to the serial bus

as described above but with address bit a4 set to 1, followed by an 8-bit dummy data word. Writing

address (a5, 1, a3, a2, a1, a0) will cause the contents (d7, d6, d5, d4, d3, d2, d1, d0) of

corresponding register (a5, 0, a3, a2, a1, a0) to be output MSB first on pin SDO (on the falling edge

of SCK). Note that pin SDO is shared with an output pin, OP[7], therefore OEB should always be

held low when register read-back data is expected on this pin. The next word may be read in to SDI

while the previous word is still being output on SDO.