Datasheet

ADS8634

ADS8638

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SBAS541A –MAY 2011– REVISED AUGUST 2011

Alarm Flag Registers for the ADS8638 (Read-Only)

The alarm conditions related to individual channels are stored in these registers. The flags can be read when an

alarm interrupt is received on the AL_PD pin. There are two types of flag for every alarm: active and tripped. The

active flag is set to '1' under the alarm condition (when data cross the alarm limit) and remains so as long as the

alarm condition persists. The tripped flag turns on the alarm condition similar to the active flag, but it remains set

until it is read. This feature relieves the device from having to track alarms.

Temp Flag: Alarm Flags Register for Temperature Sensor (Address = 20h; Page 0)

7 6 5 4 3 2 1 0

Tripped Alarm Flag Tripped Alarm Flag Active Alarm Flag Active Alarm Flag

0 0 0 0

Temperature Low Temperature High Temperature Low Temperature High

The Temp Flag register stores the alarm flags for the temperature sensor. There are two alarm thresholds, and

for each threshold there are two flags. An active alarm flag is enabled when an alarm is triggered (when data

cross the alarm threshold) and remains enabled as long as the alarm condition persists. A tripped alarm flag is

enabled in the same manner as an active alarm flag, but it remains latched until it is read.

Bit 7 Tripped Alarm Flag Temperature Low

This bit indicates the tripped low alarm flag status for the temperature sensor.

0 = No alarm detected

1 = Alarm detected

Bit 6 Tripped Alarm Flag Temperature High

This bit indicates the tripped high alarm flag status for the temperature sensor.

0 = No alarm detected

1 = Alarm detected

Bit 5 Active Alarm Flag Temperature Low

This bit indicates the active low alarm flag status for the temperature sensor.

0 = No alarm

1 = Alarm detected

Bit 4 Active Alarm Flag Temperature High

This bit indicates the active-high alarm flag status for the temperature sensor.

0 = No alarm detected

1 = Alarm detected

Bits[3:0] Always read '0'

Product Folder Link(s): ADS8634 ADS8638