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db09284e_V3.01_preliminary_2017-07-06

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AS89020

V3.01

Table 7: Addressable Register Space

ADDRESS

[HEX]

ACCESS7

NAME

NO. OF

SIGNIFICANT

BITS

DEFAULT

[HEX]

DESCRIPTION

00

wo

OSR

8

02

operational state register

01

–

–

–

–

reserved

02

ro

AGEN

8

40

API generation

03

–

–

–

–

reserved

04

–

–

–

–

reserved

05

–

–

–

–

reserved

06

rw

CREG

8

A0

configuration register

07

rw

SW_R0

6

01

transimpedance of channel 0

08

rw

SW_R1

6

01

transimpedance of channel 1

09

rw

SW_R2

6

01

transimpedance of channel 2

0A

rw

SW_R3

6

01

transimpedance of channel 3

0B

rw

CH_PD

4

0

channel Power Down

0C

rw

CH_

ORDER

8

1B

channel order for the conversion

0D

–

–

–

–

reserved

0E

–

–

–

–

reserved

0F

–

–

–

–

reserved

6.2 Operational State Register – OSR

The write-only register OSR controls the device operational state (DOS), the general Power Down mode

(PD) and the tracking behavior (TRACK) of the AS89020 according to Table 8. This register can be written

at any time, independently of the actual operational state. Please note, reading this register always returns

the value ,00h’ because the register is write-only.

Table 8: Register OSR – Address 00h

OPERATIONAL

STATE

REGISTER OSR

NAME

VALUE [B]

AFFECTED OPERATIONAL STATE

08

sample input signal or start the AD conversion

(active only in measurement state)

1

track input signal and stop AD conversion

(active only in measurement state)

08

nominal operation, no Power Down mode

1

activate Power Down mode

bit 5 to 3

-

-

reserved

7 ro – read-only, wo – write-only, rw – read-write, reading register with access write-only results in ,00h’

8 Default after power-on-reset.