AMC6821 datasheet(31/56 Pages) TI

31 / 56 page

www.ti.com

TemperatureBackinLimit

(statusbitstaysset)

HighLimit

Temperature

StatusBit

SMBALERT

ClearedonRead

(Temperaturebelowlimit)

HANDLING SMBALERT INTERRUPTS

TemperatureBackinLimit

(statusbitstaysset)

HighLimit

Temperature

StickyStatusBit

SMBALERT

Interrupt Disabled

InterruptEnabled

(

Rearmed)

SMBALERT

ClearedonRead

(temperaturebelowlimit)

AMC6821

SBAS386C – MAY 2006 – REVISED JULY 2007

Once a limit is exceeded, the corresponding status bit is set to '1'. The status bit remains set until the error

condition subsides and the status register gets read. The status bits are referred to as being sticky because they

remain set until read by software. This design ensures that out-of-limit events cannot be missed if the software is

polling the device periodically. The SMBALERT output remains low for the entire duration that the reading is out

of limits and remains low until the status register has been read. This architecture has implications on how

software handles the interrupt.

Figure 31. SMBALERT Pin and Status Bits Behavior

To prevent the system from being tied up while servicing interrupts, it is recommend to handle the SMBALERT

interrupt in this manner:

1. Detect the SMBALERT assertion.

2. Enter the interrupt handler.

3. Read the status registers to identify the interrupt source.

4. Disable the interrupt source by clearing the appropriate enable bit in the configuration registers.

5. Take the appropriate action for a given interrupt source.

6. Exit the interrupt handler.

7. Periodically poll the status registers. If the interrupt source bit has cleared, reset the corresponding interrupt

enable bit to '1'. This reset makes the SMBALERT output and status bits behave as shown in Figure 32.

Figure 32. How Masking the Interrupt Source Affects SMBALERT

Submit Documentation Feedback

Product Folder Link(s): AMC6821

AMC6821 Datasheet(PDF) 31 Page - Texas Instruments

AMC6821 Datasheet(HTML) 31 Page - Texas Instruments

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56

Datasheet Download

Link URL