MCP98243 datasheet(14/62 Pages) MICROCHIP

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MCP9843/98243

DS22153C-page 14

4.1.5

DATA VALID

After the Start condition, each bit of data in

transmission needs to be settled for a time specified by

tSU-DATA before SCL toggles from low-to-high (see

“Sensor And EEPROM Serial Interface Timing

Specifications” on Page 5).

4.1.6

ACKNOWLEDGE (ACK/NAK)

Each receiving device, when addressed, is obliged to

generate an ACK bit after the reception of each byte.

The master device must generate an extra clock pulse

for ACK to be recognized.

The acknowledging device pulls down the SDA line for

tSU-DATA before the low-to-high transition of SCL from

the master. SDA also needs to remain pulled down for

tH-DATA after a high-to-low transition of SCL.

During read, the master must signal an End-of-Data

(EOD) to the slave by not generating an ACK bit (NAK)

once the last bit has been clocked out of the slave. In

this case, the slave will leave the data line released to

enable the master to generate the Stop condition.

4.1.7

TIME OUT (MCP9843/98243,

SENSOR ONLY)

If the SCL stays low or high for time specified by tOUT,

the MCP9843/98243 temperature sensor resets the

serial interface. This dictates the minimum clock speed

as specified in the specification. However, the

EEPROM does not reset the serial interface.

Therefore, the master can hold the clock indefinitely to

process data from the EEPROM.

MCP98243 Datasheet(PDF) 14 Page - Microchip Technology