DIO1408

Version 1.0, Jul 2025

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© 2025 Dioo Microcircuits Co., Ltd. Jiangsu

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8.2.4. SMBus alert function

The SMBus alert response provides a quick fault identification for simple slave devices. The

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ALERT pin of the

DIO1408 may be connected as an SMBus alert signal while the device is in interrupt mode (TM = 1). When an

alert occurs, the master can broadcast the alert response slave address (0001100) with the read/write bit set

high. Following this alert response, any slave devices that generate an alert identifies itself by acknowledging

the alert response and sending its address on the bus. If more than one slave attempts to respond, bus

arbitration rules apply. The losing device does not generate an acknowledge and continues to hold the alert line

low until the interrupt is cleared. If the temperature is higher than THIGH or lower than TLOW, the LSB is high or low

correspondingly (see Figure 8).

Note:

(1) The value of A0 and A1 are determined by the A0 pin.

(2) S: Start, A: ACK, P: Stop,

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A: NACK.

Figure 8. SMBus alert response format

8.2.5. Timeout function

The DIO1408 integrates a timeout on its interface to prevent locking up the bus. If SCL or SDA remains low for

26 ms typically between a start and stop condition, the device resets the serial interface. The DIO1408 releases

the bus and waits for a start condition when it is pulled low.

8.2.6. High-speed (HS) mode

The DIO1408 supports bus HS mode operation and can transfer information up to 3.4 MHz. The master send

8-bit controller code (00001xxx) to indicate the beginning of an HS mode transfer. The DIO1408 switches its

internal filter to support high speed data transfer. The bus keeps operating in HS-mode until it encounters a stop

situation and the DIO1408 switches internal filters back to support the Fast-mode.

8.2.7. General call

The DIO1408 supports a general call function. When the host sends the general call address (0000000) and the

R/W bit is 0, the device responds to the general call command. If the second byte is 00000110, the DIO1408

reset internal register to power up values.