REV. 0

–26–

AD1980

Serial Configuration Register (Index 74h)

Reg

No. Name D15

D14

D13

D12

D11

D10 D9 D8

D7 D6

D5

D4

D3 D2

D1

D0

Default

74h Serial

SLOT16 REGM2 REGM1 REGM0 REGM3 DRF X

CHEN X

LBKS1 LBKS0 INTS X

SPAL SPDZ SPLNK 1001h

Configuration

All registers not shown and bits containing an X are assumed to be reserved.

Note that this register is not reset when the reset register (0x00) is written to (soft reset).

SPLNK

SPDIF Link. This bit enables the SPDIF to link with the front DACs for data requesting.

0 = SPDIF and DAC are not linked.

1 = SPDIF and DAC are linked and receive the same data requests (reset default).

SPDZ

SPDIF DACZ.

0 = Repeat last sample out of the SPDIF stream if FIFO under-runs (reset default).

1 = Forces midscale sample out the SPDIF stream if FIFO under-runs.

SPAL

SPDIF ADC Loop-around.

0 = SPDIF transmitter is connected to the AC-Link stream (reset default).

1= SPDIF transmitter is connected to the digital ADC stream, not the AC-Link.

INTS

Interrupt Mode Select. This bit selects the JS interrupt implementation path.

0 = Bit 0 SLOT 12 (modem interrupt) (reset default).

1 = Slot 6 Valid Bit (MIC ADC interrupt).

LBKS[1:0]

Loop-Back Selection. These bits select the internal digital loop-back path when LPBK bit is active (see Register 20h)

00 = Loop back through the front DACs (reset default).

01 = Loop back through the surround DACs.

10 = Reserved

11 = Loop-back through the center and LFE DACs (Center DAC loops back from the ADC left channel, the LFE

DAC from the ADC right channel).

CHEN

Chain Enable. This bit enables chaining of a slave codec SDATA_IN stream into the ID0 pin (Pin 45).

0 = Disable chaining (reset default).

1 = Enable chaining into ID0 pin.

DRF

DAC Request Force. This allows the AD1980 to synchronize DAC requests with the AD1981A/B.

0 = Normal DAC requesting sequence (reset default).

1 = Synchronize to AD1981A/B DAC requests.

REGM3

Slave 3 Codec Register Mask

REGM0

Master Codec Register Mask

REGM1

Slave 1 Codec Register Mask

REGM2

Slave 2 Codec Register Mask

SLOT16

Enable 16-Bit Slot Mode. SLOT16 makes all ac-link slots 16 bits in length, formatted into 16 slots. This is a

preferred mode for DSP serial port interfacing.