CS53L21 datasheet(29/66 Pages) CIRRUS

29 / 66 page

DS700PP1

CS53L21

4.5

Serial Port Clocking

The A/D serial audio interface port operates either as a slave or master. It accepts externally generated

clocks in slave mode and will generate synchronous clocks derived from an input master clock (MCLK) in

master mode.

The frequency of the MCLK must be an integer multiple of, and synchronous with, the system sample rate,

Fs. The LRCK frequency is equal to Fs, the frequency at which audio samples for each channel are clocked

into or out of the device.

The SPEED and MCLKDIV2 software control bits or the SDOUT/(M/S) and MCLKDIV2 stand-alone control

pins, configure the device to generate the proper clocks in Master Mode and receive the proper clocks in

Slave Mode. The value on the SDOUT pin is latched immediately after powering up in Hardware Mode.

Software

Control:

“MIC Power Control & Speed Control (Address 03h)” on page 41, “SPE Control

(Address 09h)” on page 48.

Hardware

Control:

Setting

Selection

“SDOUT, M/S” pin 29

47 k

Ω Pull-down

Slave

47 k

Ω Pull-up

Master

“MCLKDIV2” pin 2

No Divide

MCLK is divided by 2 prior

to all internal circuitry.

CS53L21 Datasheet(PDF) 29 Page - Cirrus Logic