Product ion Data WM8716
w PD Rev 4.1September 2006
13
SOFTW ARE CON TROL INTERFACE
The WM8716 can be controlled using a 3-wire serial interface. MD/DM0 (pin 26) is used for the
program data, MC/DM1 (pin 22) is used to clock in the program data and ML/I2S (pin 28) is use to
latch in the program data. The 3-wire interface protoc ol is shown in Figure 6. CSB/ IW O (pin 23) mus t
be low when writing.
ML/I2S (PIN 28)
MC/DM1 (PIN 27)
MD/DM0 (PIN 26)
B15 B14 B13 B2 B1 B0
Figure 6 Three-Wire Serial Interface
REGI STER MAP
WM8716 controls the special functions using 4 program registers, which are 16-bits long. These
registers are all loaded through input pin MD/DM0. After the 16 data bits are clocked in, ML/I2S is
used to latch in the data to the appropriate register. Table 5 shows the complete mapping of the
4 registers. Note that in hardware differential mode and 8X modes, soft ware control is not available.
The hardware differential m ode (Dif f[ 1:0] ) c l oc k l os s det ec t or dis abl e ( CDD) can onl y be ac ces s ed by
writing to M2[8:5] with the pattern 1111. Register M4 is then accessible by setting A[2:0] to 110.
B15 B14 B13 B12 B11 B10 B9 B8 B7 B6 B5 B4 B3 B2 B1 B0
M0
- - - - A2 (0) A1(0) A0(0) LDL AL7 AL6 AL5 AL4 AL3 AL2 AL1 AL0
M1
- - - - A2(0) A1(0) A0(1) LDR AR7 AR6 AR5 AR4 AR3 AR2 AR1 AR0
M2
- - - - A2(0) A1(1) A0(0) - - - - IW1 IW0 OPE DEM MUT
M3
- - - - A2(0) A1(1) A0(1) IZD SF1 SF0 CK0 REV SR0 ATC LRP I
2
S
M4
- - - - A2(1) A1(1) A0(0) - - CDD DIFF1 DIFF0 - - - -
Table 5 Mapping of Program Registers