Datasheet

PCM1753

PCM1754

PCM1755

SLES092C – OCTOBER 2003 – REVISED FEBRUARY 2009

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SOFTWARE CONTROL (PCM1753/55)

The PCM1753/55 has many programmable functions which can be controlled in the software control mode. The

functions are controlled by programming the internal registers using ML, MC, and MD.

The serial control interface is a 3-wire serial port, which operates asynchronously to the audio serial interface.

The serial control interface is used to program the on-chip mode registers. The control interface includes MD

(pin 13), MC (pin 14), and ML (pin 15). MD is the serial data input, used to program the mode registers. MC

is the serial bit clock, used to shift data into the control port. ML is the control port latch clock.

All write operations for the serial control port use 16-bit data words. Figure 23 shows the control data word

format. The most significant bit must be a 0. There are seven bits, labeled IDX[6:0], that set the register index

(or address) for the write operation. The least significant eight bits, D[7:0], contain the data to be written to the

Figure 24 shows the functional timing diagram for writing to the serial control port. ML is held at a logic 1 state

until a register needs to be written. To start the register write cycle, ML is set to logic 0. Sixteen clocks are then

provided on MC, corresponding to the 16 bits of the control data word on MD. After the sixteenth clock cycle

has completed, ML is set to logic 1 to latch the data into the indexed mode control register.

MSB

LSB

0 IDX6 IDX5 IDX4 IDX3 IDX2 IDX1 IDX0 D7 D6 D4D5 D3 D2 D1 D0

Figure 23. Control Data Word Format for MD

IDX0

D7 D6 D4D5 D3 D2 D1 D00

MD X 0

IDX6

IDX1IDX2IDX3IDX4IDX5IDX6

Figure 24. Register Write Operation