AD5522

Preliminary Technical Data

Rev. PrM | Page 38 of 48

READBACK OF SYSTEM CONTROL REGISTER

The readback function is a 24 bit word, mode, address and System Control Register data bits as shown in the following table.

Table 23. Readback System Control Register Data

Bit

Bit name

Description

23 (MSB)

MODE1

0

22

MODE0

0

SYSTEM CONTROL REGISTER SPECIFIC READBACK BITS

21

CL3

20

CL2

19

CL1

18

CL0

Readback the status of the individual Clamp Enable bits. A “0” means the clamp is disabled, while a “1” enabled.

The clamp enable function is also available in the System Control Register. This dual functionality allows flexible

enable or disabling of this function. When reading back information on the status of the clamp enable function,

what was most recently written to the clamp register from either System Control register or PMU register will be

available in the readback word.

17

CPOLH3

16

CPOLH2

15

CPOLH1

14

CPOLH0

Readback information on the Comparator Output Enable status. A “1” signifies the function is enabled, while a

“0” disabled. A logic high indicates that the PMU comparator output is enabled, while if low, it’s disabled. The

comparator output enable function is also available in the PMU Register. This dual functionality allows flexible

enable or disabling of this function. When reading back information on the status of the comparator output

enable function, what was most recently written to the comparator register from either System Control register

or PMU register will be available in the readback word.

13

CPBIASEN

This readback bit tells the status of the Comparator Enable function. A “1” in this bit position means the

Comparator functions are enabled, while a “0” disabled.

12

DUTGND/CH

DUTGND per channel enable. If this bit is set at “1”, DUTGND per channel is enabled, while if “0”, individual

guard inputs are available per channel.

11

GUARD ALM

10

CLAMP ALM

These bits give status on which of these alarm bits trigger the CGALM pin.

9

INT10K

If this bit is set high, the internal 10k resistor is connected between FOH and MEASVH, and between DUTGND

and AGND. If low, they are disconnected.

8

GUARD EN

Readback status of the Guard amplifies. If high, Amplifiers are enabled.

7

GAIN1

6

GAIN0

Status of the selected MEASOUT Output Range.

5

TMP ENABLE

4

TMP1

3

TMP0

Information is available on the status of the setting for Thermal shutdown function. Refer to System control

write register.

2

LATCHED

This bit tells of the status of the open drain outputs. When high, the open drain alarm outputs are latched

outputs, while if low, they are unlatched.

1

0 (LSB)

Unused Readback bits

Will be loaded with zeros.