AD1845

–12–

REV. C

A write to or a read from the Indexed Data Register will access the Indirect Register which is indexed by the value most recently

written to the Index Address Register. The Status Register and the PIO Data Register are always accessible directly, without

indexing. The 32 Indirect Register indexes are shown in Figure 5:

Index

Register Name

Reset/Default State

0

Left Input Control

000x

0000

1

Right Input Control

000x

0000

2

Left Aux #1 Input Control

1xx0

1000

3

Right Aux #1 Input Control

1xx0

1000

4

Left Aux #2 Input Control

1xx0

1000

5

Right Aux #2 Input Control

1xx0

1000

6

Left Output Control

1x00

0000

7

Right Output Control

1x00

0000

8

Clock and Data Format

0000

0000

9

Interface Configuration

00xx

1000

10

Pin Control

00xx

xx00

11

Test and Initialization

0000

0000

12

Miscellaneous Information

10x0

1010

13

Digital Mix/Attenuation

0000

00x0

14

Upper Base Count

0000

0000

15

Lower Base Count

0000

0000

16

Alternate Feature Enable/Left MIC Input Control

0001

0001

17

MIC Mix Enable/Right MIC Input Control

0001

000x

18

Left Line Gain, Attenuate, Mute, Mix

1xx0

1000

19

Right Line Gain, Attenuate, Mute, Mix

1xx0

1000

20

Lower Timer

0000

0000

21

Upper Timer

0000

0000

22

Upper Frequency Select

0001

1111

23

Lower Frequency Select

0100

0000

24

Capture Playback Timer

x000

0000

25

Revision ID

100x

x000

26

Mono Control

00xx

0011

27

Power-Down Control

000x

0xxx

28

Capture Data Format Control

0000

xxxx

29

Crystal Clock Select/Total Power-Down

000x

xxx0

30

Capture Upper Base Count

0000

0000

31

Capture Lower Base Count

0000

0000

“x” indicates reserved bit, always write “0s” to these bits.

Figure 5. Indirect Register Map and Reset/Default States

A detailed map of all direct and indirect register contents is summarized for reference as follows: