9/37

STA320

5.1.4 Thermal Warning Adjustable Bypass

The on-chip STA320 Power Output block provides feedback to the digital controller using inputs to the

Power Control block. The TWARN input is used to indicate a thermal warning condition.

When TWARN is asserted (set to 0) for a period of time greater than 400ms, the power control block will

force a -3dB adjustment to the modulation limit in an attempt to eliminate the thermal warning condition.

Once the thermal warning volume adjustment is applied, it remains in this state until reset.

5.1.5 hermal Warning Adjustable Bypass

The on-chip STA320 Power Output block provides feedback to the digital controller using inputs to the

Power Control block. The FAULT input is used to indicate a fault condition (either over-current or thermal).

When FAULT is asserted (set to 0), the power control block will attempt a recovery from the fault by as-

serting the tri-state output (setting it to 0 which directs the power output block to begin recovery), hold it at

0 for period of time in the range of .1ms to 1 second as defined by the Fault-Detect Recovery Constant

register (FDRC registers 29-2Ah), then toggle it back to 1. This sequence is repeated as log as the fault

indication exists. This feature is enabled by default but can be bypassed by setting the FDRB control bit

to 1.

5.2 Configuration Register B(Address 01h)

5.2.1 Serial Data Interface Format

5.2.2 Serial Data Interface

The STA320 audio serial input was designed to interface with standard digital audio components and to

accept a number of serial data formats. STA320 always acts a slave when receiving audio input from stan-

dard digital audio components. Serial data for two channels is provided using 3 inputs: left/right clock LRC-

KI, serial clock BICKI, and serial data 1 & 2 SDI12.

The SAI register (Configuration Register B - 01h, Bits D3-D0) and the SAIFB register (Configuration Reg-

ister B - 01h, Bit D4) are used to specify the serial data format. The default serial data format is I2S, MSB-

First. Available formats are shown in the tables and figure that follow.

Table 11. Serial Data First Bit

BIT

R/W

RST

NAME

DESCRIPTION

6

R/W

1

TWAB

Thermal-Warning Recovery Bypass:

0 - Thermal warning Recovery enabled

1 - Thermal warning Recovery disabled

BIT

R/W

RST

NAME

DESCRIPTION

7

R/W

0

FDRB

Fault -Detector Recovery Bypass:

0 - Fault Detector Recovery enabled

1 - Fault Detector Recovery disabled

D7

D6

D5

D4

D3

D2

D1

D0

C2IM

C1IM

DSCKE

SAIFB

SAI3

SAI2

SAI1

SAI0

100000

00

BIT

R/W

RST

NAME

DESCRIPTION

0

R/W

0

SAI0

Serial Audio Input Interface Format: Determines the interface

format of the input serial digital audio interface.

1R/W

0

SAI1

2R/W

0

SAI2

3R/W

0

SAI3

SAIFB

Format

0MSB-First

1LSB-First