STA309A13TR View Datasheet(PDF) - STMicroelectronics

Part Name

Description

Manufacturer

STA309A13TR

Multi-channel digital audio processor with DDX®

STMicroelectronics 

STA309A

Registers

Interpolation ratio select

Table 11. Interpolation ratio bits

Bit RW RST

Name

3

RW

0

IR0

4

RW

0

IR1

Description

Interpolation ratio select: selects internal interpolation

ratio based on input I2S sample frequency

The STA309A has variable interpolation (oversampling) settings such that internal

processing and DDX output rates remain consistent. The first processing block interpolates

by either 4 times, 2 times, or 1 time (pass-through).

The oversampling ratio of this interpolation is determined by the IR bits.

I

Table 12. IR sample rates

IR[1,0]

Input sample rate

fs (kHz)

00

32

00

44.1

00

48

01

88.2

01

96

10

176.4

10

192

11

DSD

1st stage interpolation ratio

4-times oversampling

4-times oversampling

4-times oversampling

2-times oversampling

2-times oversampling

Pass-through

Pass-through

DSD to 176.4 kHz conversion

Table 13. DSPB bit

Bit RW RST

Name

Description

0

RW

0

DSPB

DSP bypass bit:

0: normal operation

1: bypass of biquad and bass/treble functions

Setting the DSPB bit bypasses the biquad function of the Omega DDX core.

Table 14.

00

01

10

11

COS bits

COS[1,0]

CKOUT frequency

PLL output

PLL output / 4

PLL output / 8

PLL output / 16

Doc ID 13855 Rev 4

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